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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

L’étude de l’interaction entre les chondrocytes et le collagène modifié par le 4-Hydroxynonénal : implication dans le développement de l’arthrose

El Bikai, Rana 01 1900 (has links)
OBJECTIF: Récemment, nous avons démontré que la modification du collagène type II (Col II) par le 4-hydroxynonénal (HNE), un produit de la peroxydation lipidique, est augmentée dans le cartilage arthrosique sans qu’on sache la signification de cette augmentation dans la pathogenèse de l’arthrose. L’objectif de cette étude vise à démontrer que cette modification affecte l’interaction chondrocytes/matrice extracellulaire (MEC) et en conséquence induit des changements phénotypiques et fonctionnels de ces cellules. METHODES: Des plaques de culture ont été préalablement cotées avec du Col II puis traitées avec du HNE (0.1-2 mM) excepté le puits contrôle. Les chondrocytes ont été ensuite ensemencés puis incubés pendant 48 heures. La viabilité des cellules est évaluée par le test MTT. Le Western blot est utilisé pour mesurer l’expression des molécules d’adhésion (l’ICAM-1 et l’intégrine α1β1), de la cyclooxygenase-2 (COX-2), du Col II ainsi que la phosphorylation de la p38 MAPK, ERK1/2 et NF-κB-p65. La RT-PCR en temps réel est utilisée pour mesurer l’expression de l’ARNm de l’ICAM-1, des intégrines α1β1, de la COX-2 et de la métalloprotéinases-13 (MMP-13). La détermination de l’expression de l’ICAM-1 à la surface des cellules est réalisée par cytométrie de flux. Des kits commerciaux ont servi pour mesurer le niveau de la MMP-13, de la prostaglandine E2 (PGE2), de l’activité de la caspase-8 et de la phosphorylation de la p38 MAPK, ERK1/2 et NF-κB-p65. RESULTATS: La modification du Col II par 0.2 mM HNE induit significativement l’expression des molécules d’adhésion telles que l’ICAM-1 et l’intégrine α1β1, de la MMP-13 sans avoir un effet sur la morphologie, la survie et le phénotype cellulaires. Nos résultats montrent aussi une forte augmentation de la phosphorylation de la p38 MAPK, d’ERK1/2 et de NF-κB-p65. Cependant, la modification du Col II par 2 mM HNE affecte la morphologie et la viabilité cellulaires et induit l’activité de la caspase-8. Elle inhibe fortement l’expression des integrines α1β1 et du Col II ainsi que la phosphorylation de l’ERK1/2 et de NF-κB-p65, mais par contre, induit significativement la production de la COX-2 et son produit la PGE2 ainsi que la phosphorylation de la p38 MAPK. Fait intéressant, le prétraitement des complexes HNE/Col II par 0.1 mM de carnosine empêche les changements phénotypiques et fonctionnels des chondrocytes. CONCLUSION : Ces nouveaux résultats suggèrent le rôle important de la modification du Col II par le HNE dans l’arthrose, en affectant le phénotype et le fonctionnement cellulaires des chondrocytes. La carnosine, par sa capacité de neutraliser le HNE, a révélé d’être un agent promoteur dans le traitement de l’arthrose. / OBJECTIVE: The regulation of cell phenotype and function by the surrounding environment is deeply altered by the oxidative modifications of extracellular matrix (ECM) components that modify their structural and functional properties. This modification may be one cause involved in cartilage degradation in osteoarthritis (OA). Type II collagen (Col II) was reported to be targeted for 4-hydroxynonenal (HNE) binding, a very reactive product of lipid peroxydation. In the present study, we investigated whether HNE-binding to Col II affects OA chondrocytes phenotype and function and then, we determined the protective role of carnosine treatment in preventing these changes. METHODS: Isolated human OA chondrocytes were seeded in control wells and in HNE/Col II adducts-coated plates and incubated afterwards for 48 hours. Adhesion molecules at protein and mRNA levels were determined by Western blotting, flow cytometry and real-time RT-PCR. Commercial kits were used to evaluate cell death, caspase-8 activity and levels of prostaglandin E2 (PGE2), matrix metalloproteinase-13 (MMP-13), MAPK and NF-κB-p65. Col II, cyclooxygenase-2 (COX-2), MAPK and NF-κB-p65 levels were assessed by Western blotting. RESULTS: After 48 hours of incubation, the modification of Col II by 0.2 mM HNE induced strongly the expression of ICAM-1, integrin α1β1, MMP-13 and slightly COX-2 as well as PGE2 release without affecting cell morphology and viability as well as Col II expression. However, the modification of Col II with 2 mM HNE induced shape changes of cells from typical chondrocyte-like polygon shape to round semi-detached, affecting cells viability and inducing caspase-8 activity. It inhibited the expression of ICAM-1, integrin α1β1 and Col II, but in contrast, induced strongly PGE2 release and COX-2 expression. All these effects were prevented by 0.1 mM carnosine treatment, an HNE trapping drug. Carnosine was added to HNE-modified, Col II-coated plates 1h before cell seeding. Upon examination of different signalling pathways involved in these responses, we found that modified Col II with 2 mM HNE inhibited strongly the phosphorylation of ERK1/2 and NF-κB-p65 but induced strongly p38 MAPK. In contrast, the results indicated that MAPK and NF-κB-p65 were activated when cells were incubated with modified Col II by 0.2 mM HNE. CONCLUSION: The interaction between chondrocytes and collagen-bound HNE modulates different signalling pathways via adhesion molecules regulation and consequently leads to the expression of catabolic and inflammatory factors. Carnosine was shown to be an efficient HNE trapping agent able to counteract these effects.
32

Efeito da carnosina na prevenção de crioinjúrias no sêmen de garanhões bons e maus congeladores / Effect of carnosine on the protection against cryoinjuries in semen of good and bad freezers\' stallions

Kawai, Giulia Kiyomi Vechiato 03 March 2017 (has links)
As espécies reativas de oxigênio são fundamentais na fisiologia espermática. No entanto, um desequilíbrio entre a produção e a capacidade antioxidante caracteriza o estresse oxidativo (EO). O espermatozoide é extremamente suscetível ao EO pois, dentre outras características, a membrana plasmática é rica em ácidos graxos poli-insaturados responsáveis por promoverem a fluidez necessária em processos fisiológicos como motilidade e fertilização. Por outro lado, essas insaturações são mais facilmente oxidadas e vulneráveis à peroxidação lipídica. Em função desta susceptibilidade, estas células dependem fortemente de compostos presentes no plasma seminal (PS) para a proteção contra esse evento. Dessa forma, a carnosina, dipeptídeo presente no PS pode ser uma das responsáveis pela proteção contra o acúmulo do MDA. No entanto, durante a criopreservação do sêmen equino é necessário retirar o PS. Em estudo recente, verificamos que esta remoção, torna os espermatozoides sensíveis ao subproduto extremamente deletério da peroxidação lipídica, o malondialdeído (MDA). Como a carnosina é removida junto com o plasma seminal durante a criopreservação, foram desenvolvidos 2 experimentos sequenciais visando a melhora da qualidade do sêmen criopreservado com adição de carnosina. Amostras de sêmen de sete garanhões foram tratadas com concentrações crescentes de carnosina adicionadas ao diluidor (1mM, 50mM e 100mM). Após a descongelação, as amostras foram divididas retrospectivamente em grupos de alta congelabilidade (AC: motilidade maior que 30%) e baixa congelabilidade (BC: motilidade menor que 30%). Amostras tratadas com 50mM apresentaram menor porcentagem de células com lesão de membrana plasmática e, quando tratadas com 100mM, células com maior amplitude do deslocamento lateral de cabeça. Amostras controle BC apresentaram menor porcentagem de células com DNA íntegro em relação às amostras AC. No entanto, houve um leve aumento na porcentagem de células com DNA íntegro em amostras BC com 100mM, não diferindo das amostras AC. Por outro lado, amostras BC criopreservadas com 50mM apresentaram maiores porcentagens de células com escore calculado de potencial de membrana mitocondrial e mais suscetíveis ao EO em relação ao controle. Apesar da proteção parcial, a maior suscetibilidade à peroxidação lipídica torna-se um problema, especialmente pelo fato de que espermatozoides equinos são mais suscetíveis ao MDA. Um motivo para este efeito seria a afinidade da carnosina em reagir com açúcares, o que poderia influenciar negativamente a atividade mitocondrial e o status oxidativo, ao diminuir a produção de piruvato pela via glicolítica. Desta forma, no experimento 2, amostras BC foram tratadas com a combinação de carnosina (0 e 50mM) e piruvato (0 e 5mM) em arranjo fatorial 2x2. Verificou-se que o tratamento com piruvato (5mM) proporcionou menos células com baixa atividade mitocondrial. Por outro lado, a carnosina (50mM), promoveu maior motilidade total, progressiva e células rápidas. Houve uma tendência de aumento nas células com velocidade progressiva e atividade mitocondrial na combinação de tratamentos. Não houve diferença entre os grupos na suscetibilidade ao EO que, no entanto, correlacionou-se negativamente com células móveis, rápidas e integridade de membrana plasmática e acrossomal. Estes resultados indicam que subprodutos da peroxidação lipídica, sendo o principal deles o MDA, podem causar danos ao DNA, às mitocôndrias e à cinética espermática. Neste contexto, a carnosina (100mM) parece ter um leve efeito protetor ao DNA contra o acúmulo de MDA. Além disto, 50mM de carnosina parece auxiliar na manutenção da velocidade progressiva e atividade mitocondrial quando associada ao piruvato (5mM). Assim, a carnosina e o piruvato podem ser utilizados na prevenção de crioinjúrias em amostras de baixa congelabilidade. / Reactive oxygen species (ROS) plays a key role in the sperm physiology. However, an imbalance between ROS production and antioxidant capacity characterize the oxidative stress (OE). The spermatozoa are extremely susceptible to EO because, among other characteristics, the plasma membrane is rich in polyunsaturated fatty acids responsible for promoting fluidity necessary in physiological processes such as motility and fertilization. However, these unsaturations are more easily oxidized and vulnerable to lipid peroxidation. Due to this susceptibility, these cells strongly depend on compounds present in the seminal plasma (SP) to protect against this event. Thus, carnosine, a dipeptide present in SP of stallions, may be a key factor on the protection against MDA accumulation. Nevertheless, during the equine sperm cryopreservation process, SP is removed. In a recent study, we observed that seminal plasma removal led to an increased susceptibility of equine spermatozoa to extremely deleterious product of lipid peroxidation, malondialdehyde (MDA). As the carnosine is removed together with the seminal plasma during cryopreservation, two sequential experiments were developed aiming to improve the quality of stallion cryopreserved semen by means of carnosine therapy. Samples from seven stallions were treated with increasing concentrations of carnosine added to the extender (1mM, 50mM and 100mM) and submitted to cryopreservation. After thawing, samples were classified as high freezeability (HF: total motility greater than 30%) and low freezeability (LF: total motility lower than 30%). Samples treated with 50mM presented lower percentage of sperm showing plasma membrane damage and, when treated with 100mM, a greater amplitude of the lateral head displacement was observed. Untreated LF samples showed a lower percentage of cells showing intact DNA in relation to HF samples. By contrast, when LF samples were treated with 100mM, there was an increase in the percentage of cells with intact DNA, which was similar to the HF samples. On the other hand, LF samples cryopreserved with 50mM had a higher percentage of cells showing high calculated mitochondrial membrane potential score and increased susceptibility to OE in relation to the control. Despite the partial protection, the increased susceptibility to lipid peroxidation is a concern since equine spermatozoa is highly vulnerable to the MDA. Those results could be due to the affinity of carnosine to react with sugars, which could negatively influence mitochondrial activity and an oxidative state by decreasing pyruvate production. Hence, in experiment 2, LF samples were treated with a combination of carnosine (0 and 50mM) and pyruvate (0 and 5mM) in a 2x2 factorial arrangement. We observed that samples treated with pyruvate (5mM) had decreased percentage of cells with low mitochondrial activity. On the other hand, carnosine (50mM) increased total motility, progressive motility and fast cells. We also observed a tendency to increased progressive velocity and mitochondrial activity in the combination of treatments. There was no difference on sperm susceptibility to OE between treatments. However, this variable correlated negatively with the percentage of motile and rapid cells as well as those showing intact membrane and acrosome. These results indicate that the byproduct of lipid peroxidation (MDA) may cause damage to DNA, mitochondria and sperm kinetics. In this context, carnosine (100mM) appears to have a mild protective effect on DNA against the accumulation of MDA. Furthermore, 50mM of carnosine seems to improve progressive velocity and mitochondrial activity when associated with pyruvate (5mM). Thus, carnosine and pyruvate can be used on cryoinjuries prevention in low freezeability samples.
33

Effekt av ß-alanintillskott på Muskelkarnosin, Blodlaktat och Fysisk prestation. : En Litteraturstudie med Meta-analys / Effect of ß-alaninesupplement on Musclecarnosine, Bloodlactate and Physical performance : A Literature Study with Meta-Analysis

Fredriksson, Benjamin January 2019 (has links)
Bakgrund: Användningen av kosttillskott har ökat de senaste åren. Detta leder till att det kontinuerligt produceras nya tillskott som inte har någon evidens för effekt. Ett kosttillskott som har fått ökat intresse de senaste åren är ß-alanin. För aktiviteter där glykolys stimuleras och mjölksyraproduktionen är hög har ß-alanin föreslagits vara ett effektivt tillskott. ß-alanins effekter och funktioner i kroppen är inte helt fastställda. Syfte: Syftet med denna studie var att analysera ß-alanintillskotts effekter på muskelkarnosinkoncentrationen, blodlaktat, muskelstyrka och uthållighet/tid till utmattning.  Metod: Studien är utformad som en systematisk litteraturstudie med meta-analys. Pubmed användes som databas för litteratursökningen. Meta-analyser utfördes för karnosinkoncentration och blodlaktat.  Resultat: Dosering med 3.2g/dag av ß-alanin under 4 veckor visar signifikanta effekter på karnosinkoncentrationen. Effektstorleken på karnosinkoncetration mellan grupperna var 1.255 (p = 0.001) efter 4 veckor av supplementering. Effektstorleken mellan grupperna för 10 veckor var 2.054 (p=0.008). Inga signifikanta effekter på blodlaktat, effektstorleken mellan grupperna var 0.148 (p=0.278). Signifikant effekt av ß-alanin på tid till utmattning (TTE) vid hög-intensitets cykling. ß-alanintillskott visade signifikant effekt på en repetition max (1RM) och helkroppsstyrka (WBS). Slutsats: ß-alanintillskott med en dosering på minst 3.2g/dag i 4 veckor ger en signifikant ökning av muskelkarnosinkoncentrationen. Större dosering än 3.2g visar inte på större effekt. ß-alanin har inte någon signifikant effekt på blodlaktat. Signifikant effekt visades på TTE för hög-intensitetscykling/sprinter. ß-alanintillskotts effekt på muskelstyrka är svår identifierad eftersom det bara var två studier som kunde inkluderas. / Background: The use of dietary supplements has increased in recent years. Which leads to the continuous production of new supplements that have no evidence of effect. A dietary supplement that has gained increased interest in recent years is β-alanine. For activities where glycolysis is stimulated and lactic acid production is high, β-alanine has been suggested to be an effective supplement. The effects and functions of ß-alanine in the body are not fully established. Purpose: The purpose of this study was to analyze the effects of ß-alanine supplementation on muscle carnosine concentration, blood lactate, muscle strength and endurance/time to exhaustion. Method: The study is designed as a systematic literature study with meta-analysis. Pubmed was used as a database for the literature search. Meta-assays were performed for carnosine concentration and blood lactate. Result: Dosage at 3.2g / day of β-alanine for 4 weeks shows significant effects on carnosine concentration. The size of the effect on carnosine concentration between the groups after 4 weeks of supplementation was 1,255 (p = 0.001). The effect size between the groups for 8-10 weeks was 2,054 (p = 0.008). No significant effects on blood lactate, the effect size between the groups was 0.148 (p = 0.278). Significant effect of βalanine on time to fatigue (TTE) in high intensity cycling. β-alanine supplementation showed significant effects on a repetition max (1RM) and whole body strength (WBS). 2 Conclusion: β-alanine supplementation with a dosage of at least 3.2g / day for 4 weeks gives a significant increase in muscle carnosine concentration. Larger dosages than 3.2g does not show greater effect. β-alanine does not have a significant effect on blood lactate. Significant effect was shown on TTE for high intensity cycling sprints. The ßalanine supplemental effect on muscle strength is difficult to identify because only two studies could be included.
34

Efeitos da suplementação de β-alanina sobre a potência anaeróbia, habilidade de esforços repetidos e desempenho no polo aquático / Effects of β-alanine supplementation on the anaerobic power, repeated efforts ability and performance in water polo

Brisola, Gabriel Motta Pinheiro [UNESP] 29 September 2016 (has links)
Submitted by GABRIEL MOTTA PINHEIRO BRISOLA null (gabriel-brisola@hotmail.com) on 2016-11-18T17:48:43Z No. of bitstreams: 1 DISSERTAÇÃO ÚLTIMA VERSÃO.pdf: 3813641 bytes, checksum: c61ebbd4c02dd51b7b1ae87320fcf1d5 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-11-24T15:09:44Z (GMT) No. of bitstreams: 1 brisola_gmp_me_rcla.pdf: 3813641 bytes, checksum: c61ebbd4c02dd51b7b1ae87320fcf1d5 (MD5) / Made available in DSpace on 2016-11-24T15:09:44Z (GMT). No. of bitstreams: 1 brisola_gmp_me_rcla.pdf: 3813641 bytes, checksum: c61ebbd4c02dd51b7b1ae87320fcf1d5 (MD5) Previous issue date: 2016-09-29 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo geral do presente trabalho foi verificar o potencial ergogênico da suplementação por 4 semanas de β-alanina sobre a potência anaeróbia, habilidade de esforços repetidos e desempenho no polo aquático. 22 jogadores de elite do sexo masculino (média±dp: idade = 18±4 anos, peso = 78,5±9,5 kg e altura = 1,79±0,06 m) participaram do estudo, que foi conduzido de modo randomizado, duplo cego e placebo controlado. Os participantes foram divididos em dois grupos (β-alanina e placebo) de 11 atletas cada e foram submetidos a testes específicos (teste de habilidade de esforços repetidos (RSA) e teste máximo de 30s de salto sob o gol (30CJ)) e semi-específicos (teste de 30s máximo em nado atado (30ATADO), teste máximo de 3 minutos (All Out 3min), teste incremental máximo (GXTATADO) e performance de 200m em nado crawl (P200m)) para a modalidade e um jogo simulado para possibilitar o rastreamento das atividades realizadas por meio de filmagem. As avaliações ocorreram pré e após o período de suplementação (4 semanas). Não foram encontrados efeitos significativos de interação entre os grupos para nenhuma variável do presente estudo. No entanto, alguns ligeiros indícios de melhora com a suplementação de β-alanina foram encontrados como: (1) melhora significativa entre os momentos (pré × pós) no número total de sprints durante o jogo simulado de polo aquático; (2) efeito provavelmente benéfico (análise de inferência baseada na magnitude) para o tempo médio, pior tempo e tempo total na primeira série do teste de RSA (RSA1); (3) melhora significativa entre os momentos na força média e integral de força durante o teste 30ATADO e na P200m; (4) melhora significativa entre os momentos na força pico no teste GXTATADO. Portanto, conclui-se que a suplementação por 4 semanas de β-alanina pode promover apenas melhorar ligeiramente alguns parâmetros relacionados a habilidade de nado no polo aquático como número total de sprints em jogo simulado, tempo médio, pior tempo e tempo total no teste de RSA, força média e integral de força no 30ATADO, P200m e força crítica no GXTATADO. / The overall aim of this study was to investigate the ergogenic effect of 4 weeks β-alanine supplementation on the anaerobic power, ability to performed repeated efforts and performance of water polo. 22 male elite players (mean±SD age = 18±4 years, weight = 78.5±9.5 kg and height = 1.79±0.06 m) participated in the study, which was conducted in order randomized, double blind and placebo controlled. Participants were divided into two groups (β-alanine and placebo) of 11 athletes each and were subjected to specific tests (repeated sprint ability test (RSA) and maximum 30s jump under the goal test (30CJ)) and semi-specific (30s maximal test in tethered swimming (30TS), maximal 3 min effort (AllOut-3min), tethered swimming graded exercise test (GXTTS) and 200m in front crawl (P200m)) for the modality and a simulated game to enable tracking of the activities carried out by video record. Assessments occurred before and after the supplementation period (4 weeks). There were no significant interaction effects between the groups for any variable of this study. However, some slight improvement indications with β-alanine supplementation were found to: (1) significant improvement between moments (pre × post) the total number of sprints during the simulated game water polo; (2) probably beneficial effect (magnitude-based inference analysis) for the mean time, worst time and total time in the first series of the RSA test (RSA1); (3) significant improvement between moments for mean force and integral of force during the 30TS and P200m; (4) significant improvement between moments for peak power at GXTTS. Therefore, it is concluded that supplementation for 4 weeks of β-alanine can promote only slightly improve some parameters related to swimming ability in water polo as total number of sprints in simulated game, mean time, worst time and total time on test RSA, mean and integral of force in 30TS, P200m and critical force in GXTTS. / FAPESP: 2014/02186-7
35

Efeito da carnosina na prevenção de crioinjúrias no sêmen de garanhões bons e maus congeladores / Effect of carnosine on the protection against cryoinjuries in semen of good and bad freezers\' stallions

Giulia Kiyomi Vechiato Kawai 03 March 2017 (has links)
As espécies reativas de oxigênio são fundamentais na fisiologia espermática. No entanto, um desequilíbrio entre a produção e a capacidade antioxidante caracteriza o estresse oxidativo (EO). O espermatozoide é extremamente suscetível ao EO pois, dentre outras características, a membrana plasmática é rica em ácidos graxos poli-insaturados responsáveis por promoverem a fluidez necessária em processos fisiológicos como motilidade e fertilização. Por outro lado, essas insaturações são mais facilmente oxidadas e vulneráveis à peroxidação lipídica. Em função desta susceptibilidade, estas células dependem fortemente de compostos presentes no plasma seminal (PS) para a proteção contra esse evento. Dessa forma, a carnosina, dipeptídeo presente no PS pode ser uma das responsáveis pela proteção contra o acúmulo do MDA. No entanto, durante a criopreservação do sêmen equino é necessário retirar o PS. Em estudo recente, verificamos que esta remoção, torna os espermatozoides sensíveis ao subproduto extremamente deletério da peroxidação lipídica, o malondialdeído (MDA). Como a carnosina é removida junto com o plasma seminal durante a criopreservação, foram desenvolvidos 2 experimentos sequenciais visando a melhora da qualidade do sêmen criopreservado com adição de carnosina. Amostras de sêmen de sete garanhões foram tratadas com concentrações crescentes de carnosina adicionadas ao diluidor (1mM, 50mM e 100mM). Após a descongelação, as amostras foram divididas retrospectivamente em grupos de alta congelabilidade (AC: motilidade maior que 30%) e baixa congelabilidade (BC: motilidade menor que 30%). Amostras tratadas com 50mM apresentaram menor porcentagem de células com lesão de membrana plasmática e, quando tratadas com 100mM, células com maior amplitude do deslocamento lateral de cabeça. Amostras controle BC apresentaram menor porcentagem de células com DNA íntegro em relação às amostras AC. No entanto, houve um leve aumento na porcentagem de células com DNA íntegro em amostras BC com 100mM, não diferindo das amostras AC. Por outro lado, amostras BC criopreservadas com 50mM apresentaram maiores porcentagens de células com escore calculado de potencial de membrana mitocondrial e mais suscetíveis ao EO em relação ao controle. Apesar da proteção parcial, a maior suscetibilidade à peroxidação lipídica torna-se um problema, especialmente pelo fato de que espermatozoides equinos são mais suscetíveis ao MDA. Um motivo para este efeito seria a afinidade da carnosina em reagir com açúcares, o que poderia influenciar negativamente a atividade mitocondrial e o status oxidativo, ao diminuir a produção de piruvato pela via glicolítica. Desta forma, no experimento 2, amostras BC foram tratadas com a combinação de carnosina (0 e 50mM) e piruvato (0 e 5mM) em arranjo fatorial 2x2. Verificou-se que o tratamento com piruvato (5mM) proporcionou menos células com baixa atividade mitocondrial. Por outro lado, a carnosina (50mM), promoveu maior motilidade total, progressiva e células rápidas. Houve uma tendência de aumento nas células com velocidade progressiva e atividade mitocondrial na combinação de tratamentos. Não houve diferença entre os grupos na suscetibilidade ao EO que, no entanto, correlacionou-se negativamente com células móveis, rápidas e integridade de membrana plasmática e acrossomal. Estes resultados indicam que subprodutos da peroxidação lipídica, sendo o principal deles o MDA, podem causar danos ao DNA, às mitocôndrias e à cinética espermática. Neste contexto, a carnosina (100mM) parece ter um leve efeito protetor ao DNA contra o acúmulo de MDA. Além disto, 50mM de carnosina parece auxiliar na manutenção da velocidade progressiva e atividade mitocondrial quando associada ao piruvato (5mM). Assim, a carnosina e o piruvato podem ser utilizados na prevenção de crioinjúrias em amostras de baixa congelabilidade. / Reactive oxygen species (ROS) plays a key role in the sperm physiology. However, an imbalance between ROS production and antioxidant capacity characterize the oxidative stress (OE). The spermatozoa are extremely susceptible to EO because, among other characteristics, the plasma membrane is rich in polyunsaturated fatty acids responsible for promoting fluidity necessary in physiological processes such as motility and fertilization. However, these unsaturations are more easily oxidized and vulnerable to lipid peroxidation. Due to this susceptibility, these cells strongly depend on compounds present in the seminal plasma (SP) to protect against this event. Thus, carnosine, a dipeptide present in SP of stallions, may be a key factor on the protection against MDA accumulation. Nevertheless, during the equine sperm cryopreservation process, SP is removed. In a recent study, we observed that seminal plasma removal led to an increased susceptibility of equine spermatozoa to extremely deleterious product of lipid peroxidation, malondialdehyde (MDA). As the carnosine is removed together with the seminal plasma during cryopreservation, two sequential experiments were developed aiming to improve the quality of stallion cryopreserved semen by means of carnosine therapy. Samples from seven stallions were treated with increasing concentrations of carnosine added to the extender (1mM, 50mM and 100mM) and submitted to cryopreservation. After thawing, samples were classified as high freezeability (HF: total motility greater than 30%) and low freezeability (LF: total motility lower than 30%). Samples treated with 50mM presented lower percentage of sperm showing plasma membrane damage and, when treated with 100mM, a greater amplitude of the lateral head displacement was observed. Untreated LF samples showed a lower percentage of cells showing intact DNA in relation to HF samples. By contrast, when LF samples were treated with 100mM, there was an increase in the percentage of cells with intact DNA, which was similar to the HF samples. On the other hand, LF samples cryopreserved with 50mM had a higher percentage of cells showing high calculated mitochondrial membrane potential score and increased susceptibility to OE in relation to the control. Despite the partial protection, the increased susceptibility to lipid peroxidation is a concern since equine spermatozoa is highly vulnerable to the MDA. Those results could be due to the affinity of carnosine to react with sugars, which could negatively influence mitochondrial activity and an oxidative state by decreasing pyruvate production. Hence, in experiment 2, LF samples were treated with a combination of carnosine (0 and 50mM) and pyruvate (0 and 5mM) in a 2x2 factorial arrangement. We observed that samples treated with pyruvate (5mM) had decreased percentage of cells with low mitochondrial activity. On the other hand, carnosine (50mM) increased total motility, progressive motility and fast cells. We also observed a tendency to increased progressive velocity and mitochondrial activity in the combination of treatments. There was no difference on sperm susceptibility to OE between treatments. However, this variable correlated negatively with the percentage of motile and rapid cells as well as those showing intact membrane and acrosome. These results indicate that the byproduct of lipid peroxidation (MDA) may cause damage to DNA, mitochondria and sperm kinetics. In this context, carnosine (100mM) appears to have a mild protective effect on DNA against the accumulation of MDA. Furthermore, 50mM of carnosine seems to improve progressive velocity and mitochondrial activity when associated with pyruvate (5mM). Thus, carnosine and pyruvate can be used on cryoinjuries prevention in low freezeability samples.
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Pre-clinical investigation of carnosine’s anti-neoplastic effect on glioblastoma: uptake, signal transduction, gene expression and tumour cell metabolism

Oppermann, Henry 18 September 2020 (has links)
Das Glioblastom ist der häufigste maligne Tumor des zentralen Nervensystems. Trotz leitliniengerechter Therapie, bestehend aus mikrochirurgischer Resektion, Strahlentherapie und ergänzender Chemotherapie mit Temozolomid, beträgt die 2-Jahres-Überlebensrate nur ca. 17%. Daher sind dringend neue Therapieansätze erforderlich. Dem natürlich vorkommenden Dipeptid Carnosin, welches vor über 100 Jahren erstmals isoliert wurde, konnten viele physiologische Funktionen zugeschrieben werden. Zu Beginn unserer Arbeiten war bekannt, dass das Dipeptid das Wachstum von Krebszellen inhibiert, wobei die genauen Mechanismen der antineoplastischen Wirkungsweise weitgehend unbekannt waren. Die Untersuchungen im Rahmen der vorliegenden Habilitationsarbeit setzten sich mit möglichen Wirkmechanismen des Dipeptides auseinander, wobei ebenfalls Fragestellungen zur klinischen Anwendung von Carnosin bearbeitet wurden. Im ersten Abschnitt werden die Transportmechanismen von Carnosin in Glioblastom-Zellen beschrieben. Weiterhin wird die Frage beantwortet, ob das Dipeptid die biologisch aktive Verbindung ist oder ob L-Histidin von Carnosin abgespalten werden muss, um die antineoplastische Wirkung zu entfalten. Der zweite Abschnitt beschäftigt sich mit den Einflüssen von Carnosin auf die Signaltransduktion und Genexpression. Im dritten Abschnitt wird unter anderem mit einem Metabolomics-Ansatz der Stoffwechsel von Glioblastom-Zellen charakterisiert und der Einfluss von Carnosin auf diesen bestimmt. Im vierten Abschnitt wird ein neuartiges Ko-Kultur Modell zur Untersuchung von Carnosins Einfluss auf Glioblastom-Zell-Migration und Koloniebildung vorgestellt. Weiterhin untersuchten wir die möglichen Interaktionen des Dipeptides mit der Standardtherapie von Glioblastomen. Zusammenfassend zeigten wir, dass Carnosin durch drei verschiedene Transporter aufgenommen werden kann. Das Dipeptid hemmt sowohl Proliferation und Migration von Glioblastom-Zellen. Die Spaltung des Dipeptides ist für seine antineoplastische Wirkung nicht notwendig. In die Zelle aufgenommen, wirkt Carnosin inhibitorisch auf den Pentosephosphatweg. Eine mögliche Erklärung dafür lieferte die beobachte nicht-enzymatische Reaktion von Glycerinaldehyd-3-phosphat mit dem Dipeptid. Weiterhin zeigten unsere Experimente zum ersten Mal eine Carnosin-bedingte Veränderung der Histonacetylierung und eine damit einhergehende Beeinflussung der Genexpression. Da das Dipeptid den Effekt der Radio-/Chemotherapie verstärkt, sollte die Wirkung von Carnosin in einer klinischen Studie an Glioblastom-Patienten untersucht werden. / Glioblastoma is the most common malignant tumour of the central nervous system. Only ~17% of patients undergoing standard therapy, including microsurgical resection, radiotherapy and adjuvant chemotherapy using temozolomide survive two years after diagnosis. Hence, new therapeutic approaches are urgently needed. The naturally occurring dipeptide carnosine was discovered more than 100 years ago. Since then, many physiological functions and beneficial effects have been ascribed to it. Previous studies demonstrated that carnosine inhibits growth of cancer cells. However, at the beginning of our investigations were the mechanisms behind carnosine’s anti-neoplastic effect mostly unknown. The present work addresses possible modes of action of carnosine and issues regarding the clinical application of the dipeptide. In the first paragraph we describe the transport mechanisms of carnosine in glioblastoma cells. Furthermore, we deal with the problem whether carnosine is the biological active compound or release of L-histidine from the dipeptide is required to deploy its anti-neoplastic effect. The second paragraph addresses the influence of carnosine on glioblastoma cell signal transduction and gene expression. In the third paragraph we characterise the metabolism of glioblastoma cells and how it is influenced by carnosine by using a metabolomics approach. The fourth paragraph introduces a novel co-culture model which allows the analysis of carnosine’s impact on glioblastoma cell migration and colony formation. Furthermore, the possible interaction of the dipeptide with the glioblastoma standard therapy is investigated. In conclusion, we demonstrated that three different transporters are capable for the uptake of carnosine in glioblastoma cells. The dipeptide inhibited in addition to proliferation also migration of glioblastoma cells. Moreover, cleavage of carnosine was not required for its anti-neoplastic effect. After taken up by the cell, carnosine inhibits the pentose phosphate pathway. The observed non-enzymatic reaction of glyceraldehyde-3-phosphate with the dipeptide could possibly explain this effect. Furthermore, our experiments showed for the first time that carnosine influences gene expression by an effect on histone acetylation. As the administration of carnosine arguments the effects of radio-/chemotherapy, we encourage the clinical evaluation of the dipeptide for glioblastoma patients.
37

Erythrocytes Prevent Degradation of Carnosine by Human Serum Carnosinase

Oppermann, Henry, Elsel, Stefanie, Birkemeyer, Claudia, Meixensberger, Jürgen, Gaunitz, Frank 18 January 2024 (has links)
The naturally occurring dipeptide carnosine (-alanyl-L-histidine) has beneficial effects in different diseases. It is also frequently used as a food supplement to improve exercise performance and because of its anti-aging effects. Nevertheless, after oral ingestion, the dipeptide is not detectable in human serum because of rapid degradation by serum carnosinase. At the same time, intact carnosine is excreted in urine up to five hours after intake. Therefore, an unknown compartment protecting the dipeptide from degradation has long been hypothesized. Considering that erythrocytes may constitute this compartment, we investigated the uptake and intracellular amounts of carnosine in human erythrocytes cultivated in the presence of the dipeptide and human serum using liquid chromatography–mass spectrometry. In addition, we studied carnosine’s effect on ATP production in red blood cells and on their response to oxidative stress. Our experiments revealed uptake of carnosine into erythrocytes and protection from carnosinase degradation. In addition, no negative effect on ATP production or defense against oxidative stress was observed. In conclusion, our results for the first time demonstrate that erythrocytes can take up carnosine, and, most importantly, thereby prevent its degradation by human serum carnosinase.
38

Investigação dos mecanismos biológicos de detoxificação de aldeídos α,β- insaturados em ratos SODG93A modelo para ALS / Investigation of the α,β- unsaturated aldehydes biological detoxification mechanism in SODG93A rats model to ALS

Bispo, Vanderson da Silva 15 September 2015 (has links)
A lipoperoxidação gera diversas espécies carbonílicas altamente reativas dentre as quais se destacam acroleína (ACR), malondialdeído (MDA), 4-hidroxi-2-hexenal (HHE) e 4-hidroxi-2-nonenal (HNE). A principal via endógena de metabolização desses compostos é através de conjugação com glutationa por ação da glutationa-S-tranferase. Contudo, diversos trabalhos têm mostrado que dipeptídeos contendo histidina, tal como a carnosina (CAR), também podem formar conjugados com aldeídos e auxiliar na detoxificação desses compostos. Em nosso trabalho adutos de CAR com ACR, HHE, HHEd5, HNE e HNEd11 foram sintetizados, purificados e caracterizados. A reação da CAR com ACR foi estudada em detalhes. Resultados mostraram que a carnosina reage com acroleína formando 03 produtos principais: m/z = 265, m/z = 283 e m/z = 303, sendo este último mais estável e mais abundante. Dados de RMN H1, COSY e HSQC permitiram elucidar a estrutura dessa molécula (m/z = 303) e propor uma rota de reação. Em seguida, uma metodologia baseada em cromatografia líquida acoplada à espectrometria de massas do tipo \"Ion Trap\" (ESI+ HPLC/MS-MS) foi desenvolvida e validada para quantificação simultânea dos adutos sintetizados. Pelo método desenvolvido é possível quantificar com precisão 25 pmol de CAR-HHE, 1 pmol de CAR-ACR e 1 pmol de CAR-HNE com um coeficiente de variação de aproximadamente 10 % e acurácia de 98 % (HHEd5 e HNEd11 foram usados como padrão interno). Análise em urina de adultos não fumantes mostraram que os produtos sintetizados estão presentes na urina de humanos em concentrações de 3,6 ± 1,4; 2,3 ± 1,5 e 1,3 ± 0,5 nmol / mg de creatinina, respectivamente para CAR-ACR, CAR-HHE e CAR-HNE. Em ratos transgênicos SODG93A modelo para esclerose lateral amiotrófica (ELA), a suplementação da dieta dos animais com 35 ± 5 mg carnosina/animal/semana melhorou a manutenção do peso e a sobrevida dos animais. Análises dos adutos sintetizados em amostras de músculo sugerem que a metabolização de aldeídos esteja comprometida nesses animais e que a carnosina poderia funcionar como \"scavenger\" para esses compostos. Esses resultados comprovam que dipeptídeos de histidina atuam na detoxificação de compostos carbonílicos e participa de suas vias de excreção. Além disso, a caracterização da estrutura e desenvolvimento de método sensível de detecção abre a possibilidade de utilização desses adutos como biomarcadores de estresse redox e exposição a aldeídos. / Lipid peroxidation generates reactive carbonyl species, including 4-hydroxy-2-nonenal (HNE), acrolein (ACR), 4-hydroxy-2-hexenal (HHE) and malondialdehyde (MDA). One major pathway of aldehyde detoxification in vivo is through conjugation with glutathione catalyzed by glutathione-S-transferases or, alternatively, by conjugation with endogenous histidine containing dipeptides, such as carnosine (CAR). The reaction of CAR with ACR was investigated in an effort to assess its possible biological role. One stable adduct was isolated by reverse-phase HPLC and characterized on the basis of extensive spectroscopic measurements. The proposed reaction route for product formation involves the reaction of the CAR amino group with ACR via a Schiff base formation followed by dehydration and cyclization through Michael addition in the imidazole ring forming an instable compound with m/z = 265. The subsequent reaction with another molecule of ACR followed by cyclization gives rise to the final product with m/z = 303.A highly sensitive method involving HPLC-MS analysis was developed for the simultaneous accurate quantification of CAR- ACR, CAR-HHE and CAR-HNE adducts in human urinary samples from non-smoking adults. This methodology permits quantification of 10 pmol CAR-HHE and 1 pmol of CAR-ACR and CAR-HNE. Adduct levels in urine were 3.6 ± 1.4, 2.3 ± 1.5, 1.3 ± 0.5 nmol/mg of creatinine, respectively to CAR-ACR, CAR-HHE and CAR-HNE. In SODG93A transgenic rats model to amyotrophic lateral sclerosis (ALS), the food supplementation of the animals with 35 ± 5 mg carnosine/animal/week improve de body weight and the life span of the ALS treated group. Analysis of the synthesized adducts in muscle sample showed suggest than aldehyde metabolization is compromised in this animals and that may be carnosine work like a scavenger for these compounds. Our results indicate that carnosine adduction can be an important detoxification route of α,β -unsaturated aldehydes. Moreover, carnosine adducts quantification may be useful as redox stress indicator in vivo.
39

Avaliação da espectroscopia de ressonância magnética para quantificação de carnosina muscular em humanos / Evaluation of magnetic resonance spectroscopy for quantification of muscle carnosine in humans

Vinícius da Eira Silva 01 August 2017 (has links)
Introdução: A carnosina (beta-Alanil-L-Histidina) é um dipeptídeo encontrado em altas concentrações em diversos tecidos excitáveis, tais como o coração, cérebro e músculo. Embora o número de evidencias sobre os efeitos benéficos da carnosina esteja aumentando, muitos desses estudos apresentam uma importante limitação: a falta de mensuração da carnosina intramuscular. O principal motivo é a necessidade de realização de biópsias musculares. Nesse sentido, um novo método não invasivo baseado na ressonância magnética de hidrogênio (1H RNM) foi apresentado como alternativa. Objetivos: Determinar a reprodutibilidade, acurácia e sensibilidade do 1H MRN na determinação do conteúdo de carnosina muscular em seres humanos contra a referência \"padrão-ouro\" de quantificação de carnosina, cromatografia líquida de alta eficiência (HPLC) em extratos musculares obtidas por biópsia muscular. Métodos: O estudo foi dividido em duas sub-investigações, sendo a primeira delas uma investigação in vitro que testou a linearidade do sinal da carnosina na 1H RMN. Para a segunda investigação dezesseis homens fisicamente ativos (18 - 35 anos) sem doença crônico-degenerativa ou qualquer disfunção no aparelho locomotor se voluntariaram. Os participantes foram submetidos a duas sessões no total. Na sessão inicial, características antropométricas e de composição corporal foram mensuradas, cada indivíduo teve sua concentração de carnosina muscular do gastrocnêmio avaliada através da análise 1H MRN (um teste-reteste foi realizado com uma sub amostra para verificar a reprodutibilidade do método), em seguida uma biópsia muscular do gastrocnêmio foi realizada. Os voluntários então se submeteram a um período de quatro semanas de suplementação de 6,4 g. de beta-alanina por dia, estimulo que comprovadamente aumenta a carnosina muscular, durante esse período também foi realizada uma avaliação nutricional para determinar a quantidade carnosina ingerida em suas dietas. Na segunda sessão os indivíduos mais uma vez tiveram suas composições corporais avaliadas e realizaram o teste de 1H RMN e biópsia muscular para acessar suas concentrações de carnosina muscular. Resultados: In vitro: A linearidade de sinal de 1H RMN para as concentrações de carnosina testadas apresentou valores de R2 de 0,9771. In vivo: O teste-reteste da 1H RMN apresentou coeficiente de variação médio de 9,9 ± 10,34% e coeficiente de correlação interclasse de = 0,775 (95% C.I.: 0,324-0,939). Comparando-se os dois métodos: As concentrações de carnosina (em mmol/kg musculo seco) não foram estatisticamente diferentes tanto no pré (1H RMN -20,8±6,2; HPLC -23,3±10,5; p=0,45; 95% CI= -4,5 -9,6) quanto no pós-suplementação (1H RMN - 35,2±13,2; HPLC-27,8±11,7; p=0,15; 95% CI= -3,5 - 17,8) (n=13). Os valores de delta da concentração de carnosina muscular (em %) também não foram estatisticamente diferentes (1H RMN - 69,7±66,7; HPLC -38,2±58,2 p=0,16; 95% CI= -14,5 -77,5; ES=0,90). Ao observar os dados individuais, nota-se também baixa correlação dos dados individuais entre os métodos (R2 = 0,0448; r =0,212; p= 0,229). Conclusão: A 1H RMN apresentou baixa reprodutibilidade e acurácia quando comparada ao padrão ouro (HPLC), não sendo possível sua utilização para mensuração de carnosina muscular / Introduction: Carnosine (beta-Alanyl-L-Histidine) is a dipeptide found in high-concentrations in human tissue, such as heart, brain and muscle tissue. Although the body of evidence relating beneficial effects of carnosine is increasing, most of these studies have an important limitation: the lack of intramuscular carnosine measurement. The main reason for the absence of this measurement is the method of analysis; a muscle sample must be obtained via a muscle biopsy. In this regard, a new method non-invasive based on hydrogen magnetic resonance (1H NMR) has been used as an alternative. Objectives: The present study aims to determine the reproducibility, accuracy, and sensitivity of H-MRS in the determination of muscle carnosine content in humans; comparative data analysis will be performed against the \"standard\" reference of HPLC carnosine quantification in muscle extracts obtained by muscle biopsy. Methods: The study was divided into two sub-investigations. The first of which was an in vitro investigation that tested the linearity of the carnosine signal at 1 H NMR. For the second investigation, sixteen physically active men (18-35 years) without chronic-degenerative disease or any dysfunction in the locomotor apparatus volunteered. The participants were submitted to 2 sessions in total; Upon arrival to the initial session, anthropometric and body composition characteristics were collected before each individual underwent a muscle carnosine measurement of the gastrocnemius via H-MRS analysis (a test-retest was performed with a sub-sample to verify the reproducibility of the method) followed by a gastrocnemius muscle biopsy. Thereafter volunteers were submitted to a 4-week supplementation period of 6.4 g. of beta-alanine per day, a stimulus proven to increase muscle carnosine, during this period, volunteers had their carnosine dietary ingestion evaluated as well. Following the supplementation period, individuals were subjected to another body composition evaluation, 1H RMN and muscle biopsy. Results: In vitro: The linearity of 1 H NMR signal for carnosine concentrations tested showed R2 values of 0.9771. In vivo: 1 H NMR test-retest showed a mean coefficient of variation of 9.9 ± 10.34% and ICC= 0.775 (95% C.I.: 0.324-0.939).Comparing the methods: Carnosine concentrations (in mmol / kg dry muscle) were not significant difference either the in pre (1 H NMR -20.8 ± 6.2, HPLC -23.3 ± 10, 5, p = 0.45, 95% CI = -4.5 -9.6) and post-supplementation (1 H NMR - 35.2 ± 13.2, HPLC-27.8 ± 11.7, p = 0.15, 95% CI = -3.5-17.8) . The delta values of muscle carnosine concentration (in %) were not statistically different (1 H NMR - 69.7 ± 66.7; HPLC -38.2 ± 58.2 p = 0.16; 95 % CI = -14.5 -77.5; ES = 0.90). Comparing the individual data, there was a low correlation between the methods (R2 = 0.0448, r = 0.212, p = 0.229). Conclusion: 1H NMR showed low reproducibility and accuracy when compared to the gold standard (HPLC), not being possible its use for carnosine quantification
40

Avaliação da espectroscopia de ressonância magnética para quantificação de carnosina muscular em humanos / Evaluation of magnetic resonance spectroscopy for quantification of muscle carnosine in humans

Silva, Vinícius da Eira 01 August 2017 (has links)
Introdução: A carnosina (beta-Alanil-L-Histidina) é um dipeptídeo encontrado em altas concentrações em diversos tecidos excitáveis, tais como o coração, cérebro e músculo. Embora o número de evidencias sobre os efeitos benéficos da carnosina esteja aumentando, muitos desses estudos apresentam uma importante limitação: a falta de mensuração da carnosina intramuscular. O principal motivo é a necessidade de realização de biópsias musculares. Nesse sentido, um novo método não invasivo baseado na ressonância magnética de hidrogênio (1H RNM) foi apresentado como alternativa. Objetivos: Determinar a reprodutibilidade, acurácia e sensibilidade do 1H MRN na determinação do conteúdo de carnosina muscular em seres humanos contra a referência \"padrão-ouro\" de quantificação de carnosina, cromatografia líquida de alta eficiência (HPLC) em extratos musculares obtidas por biópsia muscular. Métodos: O estudo foi dividido em duas sub-investigações, sendo a primeira delas uma investigação in vitro que testou a linearidade do sinal da carnosina na 1H RMN. Para a segunda investigação dezesseis homens fisicamente ativos (18 - 35 anos) sem doença crônico-degenerativa ou qualquer disfunção no aparelho locomotor se voluntariaram. Os participantes foram submetidos a duas sessões no total. Na sessão inicial, características antropométricas e de composição corporal foram mensuradas, cada indivíduo teve sua concentração de carnosina muscular do gastrocnêmio avaliada através da análise 1H MRN (um teste-reteste foi realizado com uma sub amostra para verificar a reprodutibilidade do método), em seguida uma biópsia muscular do gastrocnêmio foi realizada. Os voluntários então se submeteram a um período de quatro semanas de suplementação de 6,4 g. de beta-alanina por dia, estimulo que comprovadamente aumenta a carnosina muscular, durante esse período também foi realizada uma avaliação nutricional para determinar a quantidade carnosina ingerida em suas dietas. Na segunda sessão os indivíduos mais uma vez tiveram suas composições corporais avaliadas e realizaram o teste de 1H RMN e biópsia muscular para acessar suas concentrações de carnosina muscular. Resultados: In vitro: A linearidade de sinal de 1H RMN para as concentrações de carnosina testadas apresentou valores de R2 de 0,9771. In vivo: O teste-reteste da 1H RMN apresentou coeficiente de variação médio de 9,9 ± 10,34% e coeficiente de correlação interclasse de = 0,775 (95% C.I.: 0,324-0,939). Comparando-se os dois métodos: As concentrações de carnosina (em mmol/kg musculo seco) não foram estatisticamente diferentes tanto no pré (1H RMN -20,8±6,2; HPLC -23,3±10,5; p=0,45; 95% CI= -4,5 -9,6) quanto no pós-suplementação (1H RMN - 35,2±13,2; HPLC-27,8±11,7; p=0,15; 95% CI= -3,5 - 17,8) (n=13). Os valores de delta da concentração de carnosina muscular (em %) também não foram estatisticamente diferentes (1H RMN - 69,7±66,7; HPLC -38,2±58,2 p=0,16; 95% CI= -14,5 -77,5; ES=0,90). Ao observar os dados individuais, nota-se também baixa correlação dos dados individuais entre os métodos (R2 = 0,0448; r =0,212; p= 0,229). Conclusão: A 1H RMN apresentou baixa reprodutibilidade e acurácia quando comparada ao padrão ouro (HPLC), não sendo possível sua utilização para mensuração de carnosina muscular / Introduction: Carnosine (beta-Alanyl-L-Histidine) is a dipeptide found in high-concentrations in human tissue, such as heart, brain and muscle tissue. Although the body of evidence relating beneficial effects of carnosine is increasing, most of these studies have an important limitation: the lack of intramuscular carnosine measurement. The main reason for the absence of this measurement is the method of analysis; a muscle sample must be obtained via a muscle biopsy. In this regard, a new method non-invasive based on hydrogen magnetic resonance (1H NMR) has been used as an alternative. Objectives: The present study aims to determine the reproducibility, accuracy, and sensitivity of H-MRS in the determination of muscle carnosine content in humans; comparative data analysis will be performed against the \"standard\" reference of HPLC carnosine quantification in muscle extracts obtained by muscle biopsy. Methods: The study was divided into two sub-investigations. The first of which was an in vitro investigation that tested the linearity of the carnosine signal at 1 H NMR. For the second investigation, sixteen physically active men (18-35 years) without chronic-degenerative disease or any dysfunction in the locomotor apparatus volunteered. The participants were submitted to 2 sessions in total; Upon arrival to the initial session, anthropometric and body composition characteristics were collected before each individual underwent a muscle carnosine measurement of the gastrocnemius via H-MRS analysis (a test-retest was performed with a sub-sample to verify the reproducibility of the method) followed by a gastrocnemius muscle biopsy. Thereafter volunteers were submitted to a 4-week supplementation period of 6.4 g. of beta-alanine per day, a stimulus proven to increase muscle carnosine, during this period, volunteers had their carnosine dietary ingestion evaluated as well. Following the supplementation period, individuals were subjected to another body composition evaluation, 1H RMN and muscle biopsy. Results: In vitro: The linearity of 1 H NMR signal for carnosine concentrations tested showed R2 values of 0.9771. In vivo: 1 H NMR test-retest showed a mean coefficient of variation of 9.9 ± 10.34% and ICC= 0.775 (95% C.I.: 0.324-0.939).Comparing the methods: Carnosine concentrations (in mmol / kg dry muscle) were not significant difference either the in pre (1 H NMR -20.8 ± 6.2, HPLC -23.3 ± 10, 5, p = 0.45, 95% CI = -4.5 -9.6) and post-supplementation (1 H NMR - 35.2 ± 13.2, HPLC-27.8 ± 11.7, p = 0.15, 95% CI = -3.5-17.8) . The delta values of muscle carnosine concentration (in %) were not statistically different (1 H NMR - 69.7 ± 66.7; HPLC -38.2 ± 58.2 p = 0.16; 95 % CI = -14.5 -77.5; ES = 0.90). Comparing the individual data, there was a low correlation between the methods (R2 = 0.0448, r = 0.212, p = 0.229). Conclusion: 1H NMR showed low reproducibility and accuracy when compared to the gold standard (HPLC), not being possible its use for carnosine quantification

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