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Efeitos da l-alanil-glutamina na isquemia e reperfusÃo em cÃrebro de ratos wistar / Effects of l-alanyl-glutamine in ischemia and reperfusion in the brain of Wistar ratsAndrÃa da NÃbrega Cirino 09 September 2009 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O objetivo do presente estudo foi verificar os efeitos da L-alanil-glutamina (Ala-Gln) na isquemia e reperfusÃo em cÃrebro de ratos. Foram utilizados 48 ratos machos, da linhagem Wistar, com idade mÃdia de 62 dias e peso mÃdio de 276,38g, distribuÃdos em quatro grupos: Sham 30 minutos, Isquemia, Sham 90 minutos e Isquemia/ ReperfusÃo. Foi utilizado um modelo de isquemia cerebral experimental global, com oclusÃo da artÃria carÃtida comum bilateral e administraÃÃo de soluÃÃo salina ou Ala-Gln. Os resultados do presente estudo mostraram elevaÃÃo estatisticamente significante no percentual de Ãrea de necrose do grupo Isquemia (13,24  8,82) em relaÃÃo ao grupo Sham 30 minutos (0,12  0,20, p= 0,01). O mesmo ocorreu em relaÃÃo à Ãrea de necrose do grupo Isquemia/ReperfusÃo (13,30  9,91) em relaÃÃo ao Sham 90 minutos (0,70  1,35, p= 0,01). Tais resultados demonstram a efetividade do modelo Isquemia e Isquemia/ReperfusÃo cerebrais utilizados. NÃo foi observada alteraÃÃo significante no percentual de Ãrea de necrose entre os grupos Isquemia Salina (13,24  8,82) e Isquemia Ala-Gln (15,35  6,80, p= 0,34). A mÃdia do percentual de Ãrea isquÃmica do grupo Isquemia/ReperfusÃo Ala-Gln (4,65  1,44) foi significantemente inferior Ãquela encontrada no grupo Isquemia/ReperfusÃo Salina (13,30  9,91, p= 0,03). A administraÃÃo prÃvia de Ala-Gln a ratos submetidos à Isquemia/reperfusÃo cerebral nÃo promoveu reduÃÃo no percentual de Ãrea de necrose na lesÃo isquÃmica. Por outro lado, esse dipeptÃdeo reduziu o percentual de necrose cerebral na lesÃo Isquemia/ReperfusÃo cerebral. / The aim of this study was to investigate the effects of L-alanyl-glutamine (Ala-Gln) in ischemia and reperfusion in rat brain. We used 48 male rats, Wistar, with a mean age of 62 days and average weight of 276.38 g, divided into four groups: Sham 30 minutes ischemia, 90 minutes and Sham Ischemia / Reperfusion. We used a model of experimental global cerebral ischemia with occlusion of bilateral common carotid artery and administration of saline or Ala-Gln. The results of this study showed a statistically significant increase in the percentage of necrotic area of the ischemia group (13.24  8.82) than in group Sham 30 minutes (0.12  0.20, p= 0.01). The same occurred in relation to the area of necrosis in ischemia-reperfusion group (13.30  9.91) compared to Sham 90 minutes (0.70  1.35, p= 0.01). These results demonstrate the effectiveness of the model Ischemia and Ischemia / Reperfusion brain used. There was no significant change in the percentage of necrotic area between Salina ischemia groups (13.24  8.82) and ischemia Ala-Gln (15.35  6.80, p= 0.34). The average percentage of ischemic area of group Ischemia / Reperfusion Ala-Gln (4.65  1.44) was significantly lower than that in group Ischemia / Reperfusion Salina (13.30  9.91, p= 0.03). The prior administration of Ala-Gln in rats subjected to ischemia / reperfusion did not cause reduction in the percentage of necrosis in ischemic injury. Moreover, this dipeptide reduced the percentage of necrosis in the cerebral injury cerebral ischemia / reperfusion.
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Oxidative stress : natural history and modulation In surgery and trauma patientsObayan, Adebola Okunola Emeka 31 August 2004
Oxidative stress has been associated with many disease conditions in adults and neonates based on clinical and post mortem studies. Trauma is the commonest cause of oxidative stress. However a gap in knowledge of the natural history of oxidative stress in humans was identified as most studies have been post mortem or in animals. <p>The aim of this research is to understand treat and oxidative stress in trauma and surgical patients. The study involved three components including: the development and evaluation of the novel oxistress assay; study of clinical trauma and oxidative stress; and clinical trial of alanyl-glutamine supplementation following major surgery. The novel oxistress assay was used on urine samples in the normal population to determine reference values and subsequently on hospital patients to determine sensitivity and specificity. The study of clinical trauma and oxidative stress evaluated plasma antioxidants (FRAP assay), red cell glutathione (Asensis method), plasma and urine protein carbonyl (Levines method) and total oxidants in plasma and urine (oxistress assay) over 7 day period following trauma. The clinical trial was a double blind study of 69 major surgery patients evaluating biochemical and clinical parameters over 7 day period in comparison with pre-operative status. <p>The novel oxistress assay proves to be a sensitive and accurate bedside diagnostic tool for oxidative stress. It can also be used in the laboratory setting. Oxidative stress is associated with increased trauma severity resulting in antioxidant depletion, strong oxidant production and protein degradation. The presence of pre-morbid medical factors also increased oxidative stress in trauma patients. Oral alanyl-glutamine supplementation (0.3 g/kg) increased plasma glutamine and antioxidant levels while decreasing urine oxidant levels. It significantly reduced hospital stay in non-cancer and higher disease complexity patients. The intervention also reduced the resource intensity weighting (RIW) score. <p>Oxidative stress is a clinical problem in surgery and trauma patients that can now be easily diagnosed at the bedside using the novel oxistress assay. Treatment with alanyl-glutamine is effective in reducing oxidative stress and improving clinical outcome. It is highly recommended probably at a higher dose in order to achieve optimal results.
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Oxidative stress : natural history and modulation In surgery and trauma patientsObayan, Adebola Okunola Emeka 31 August 2004 (has links)
Oxidative stress has been associated with many disease conditions in adults and neonates based on clinical and post mortem studies. Trauma is the commonest cause of oxidative stress. However a gap in knowledge of the natural history of oxidative stress in humans was identified as most studies have been post mortem or in animals. <p>The aim of this research is to understand treat and oxidative stress in trauma and surgical patients. The study involved three components including: the development and evaluation of the novel oxistress assay; study of clinical trauma and oxidative stress; and clinical trial of alanyl-glutamine supplementation following major surgery. The novel oxistress assay was used on urine samples in the normal population to determine reference values and subsequently on hospital patients to determine sensitivity and specificity. The study of clinical trauma and oxidative stress evaluated plasma antioxidants (FRAP assay), red cell glutathione (Asensis method), plasma and urine protein carbonyl (Levines method) and total oxidants in plasma and urine (oxistress assay) over 7 day period following trauma. The clinical trial was a double blind study of 69 major surgery patients evaluating biochemical and clinical parameters over 7 day period in comparison with pre-operative status. <p>The novel oxistress assay proves to be a sensitive and accurate bedside diagnostic tool for oxidative stress. It can also be used in the laboratory setting. Oxidative stress is associated with increased trauma severity resulting in antioxidant depletion, strong oxidant production and protein degradation. The presence of pre-morbid medical factors also increased oxidative stress in trauma patients. Oral alanyl-glutamine supplementation (0.3 g/kg) increased plasma glutamine and antioxidant levels while decreasing urine oxidant levels. It significantly reduced hospital stay in non-cancer and higher disease complexity patients. The intervention also reduced the resource intensity weighting (RIW) score. <p>Oxidative stress is a clinical problem in surgery and trauma patients that can now be easily diagnosed at the bedside using the novel oxistress assay. Treatment with alanyl-glutamine is effective in reducing oxidative stress and improving clinical outcome. It is highly recommended probably at a higher dose in order to achieve optimal results.
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AvaliaÃÃo dos mecanismos de proliferaÃÃo e tipos de morte celular na lesÃo induzida pela Escherichia coli enteroagregativa e sua modulaÃÃo por alanil-glutamina e betacarotenoMara de Moura Gondim Prata 15 February 2013 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / A Escherichia coli enteroagregativa (EAEC) està entre os mais importantes agentes associados Ãs doenÃas diarreicas persistentes (DP) e mostrou-se prevalente em estudos na populaÃÃo infantil em comunidades carentes da cidade de Fortaleza. A EAEC causa lesÃo e inflamaÃÃo intestinal levando a DP e, quando associada à desnutriÃÃo, pode ocasionar um dÃficit cognitivo e reduÃÃo do crescimento infantil. Este estudo analisou in vitro (IEC-6 e HEp-2), o papel da alanil-glutamina (AG) e do betacaroteno nos mecanismos de proliferaÃÃo, apoptose e necrose e em resposta a lesÃo intestinal induzida por uma cepa EAEC selvagem (LDI001), uma cepa controle EAEC 042 e uma cepa de E. coli HS comensal. A cepa LDI001 foi isolada de uma crianÃa desnutrida. Na viabilidade celular houve uma reduÃÃo significativa (p<0.05) pÃs-infecÃÃo com as EAECs nas concentraÃÃes de 105UFC/mL nos tempos de 12, 24 e 48 horas. Contudo, a cepa comensal apenas alterou no tempo tardio (48h). As cÃlulas lesionadas por EAEC diminuÃram a transcriÃÃo (p<0.05) do mRNA dos genes c-jun e c-fos e, apenas tardiamente (12h), com a cepa comensal. A apoptose celular aumentou (p<0.05) apÃs a infecÃÃo com todas as cepas em 24h. PorÃm, o dano persistiu elevado apenas nas cÃlulas tratadas com as cepas de EAEC. A cepa 042 aumentou as cÃlulas necrÃticas (p<0.05) em todos os tempos, embora a LDI001 causou o dano apenas em 24h.Todas as cÃlulas infectadas sofreram aumento da transcriÃÃo (p<0.05) de caspase 8 em 12h. Houve aumento trascricional (p<0.05) de NF-kB em 12h nas cÃlulas infectadas. Enquanto os nÃveis de transcriÃÃo de IL-8 foram altos imediatamente ao termino da infecÃÃo (0h) e houve reduÃÃo em 12h. A LDI001 causou reduÃÃo da viabilidade celular vinculada à sua aÃÃo apoptÃtica. A EAEC 042 induziu danos tanto pela apoptose como a necrose celular. A cepa comensal mostrou um perfil diferenciado das outras cepas provavelmente por nÃo apresentar genes de virulÃncia. A suplementaÃÃo com AG 1mM foi capaz de aumentar a proliferaÃÃo celular (p<0.05) associado a reduÃÃo da apoptose e necrose (p<0.05) nas cÃlulas pÃs-infectadas nos tempos de 12, 24 e 48h. Contudo, a presenÃa de AG 1mM nas cÃlulas infectadas nÃo alterou os baixos nÃveis transcricionais de c-jun e c-fos promovidos pela infecÃÃo, e nÃo conseguiu bloquear a transcriÃÃo significante (p<0.05) de caspase 8. Os nÃveis de transcriÃÃo de NF-kB ainda permaneceu aumentado (p<0.05) na presenÃa de AG em cÃlulas pÃs-infectadas no tempo de 12h. Percebeu-se a continua reduÃÃo temporal da transcriÃÃo de IL-8 nÃo estava associada ao tratamento das cÃlulas infectadas com AG 1mM. A suplementaÃÃo com AG obteve efeitos positivos na proteÃÃo epitelial contra os danos causados pela infecÃÃo das cepas tanto nos processos proliferativos quanto na inibiÃÃo de morte celular. Contudo, a alanil-glutamina nÃo bloqueou a transcriÃÃo de caspase 8 podendo sua funÃÃo antiapoptÃtica estar relacionada a outra via de aÃÃo no presente modelo em estudo. O tratamento com betacaroteno promoveu a reversÃo do dano na viabilidade celular significativa (p<0.05) apenas em 24h apÃs infecÃÃo. Enquanto a presenÃa do betacaroteno em cÃlulas pÃs-infectadas com EAEC selvagem causou aumento de apoptose e necrose (p<0.05) em 48h. CÃlulas infectadas tratadas com betacaroteno nÃo aumentaram os nÃveis de c-jun e c-fos e tambÃm nÃo conseguiram bloquear a transcriÃÃo de caspase 8 e aumentaram (p<0.05) os nÃveis de caspase 3 no tempo de 12h. O betacaroteno mostrou-se potencialmente lesivo Ãs cÃlulas causando morte celular, provavelmente, relacionado aos seus efeitos prooxidantes. / Enteroaggregative Escherichia coli (EAEC) is among the most important agents associated with persistent diarrhea (DP) and was prevalent in studies in children in poor communities in the city of Fortaleza. EAEC cause intestinal injury and inflammation leading to DP and, when combined with malnutrition, can cause a cognitive deficit and infant growth impairment. The current study examined in vitro (IEC-6 and HEp-2) intestinal pathophysiology of three strains: EAEC wild type, EAEC 042 (positive control) and non-pathogenic E.coli HS as well as the role of alanyl-glutamine (AG) and beta-carotene in the mechanisms of proliferation, apoptosis and necrosis in response to the injury caused by EAEC strains. The wild type strain was isolated from a malnourished child. Intestinal cells viability assay in showed a significant reduction (p<0.05) after post-infection with EAEC strains at concentrations of 105UFC/mL in 12, 24 and 48 hours. However, the E.coli HS only changed the intestinal cell viability after 48 hours. EAEC post-infected intestinal cells presented mRNA transcription decrease (p<0.05) of c-jun and c-fos at the period of zero, 6 and 12 hours after infection was terminated, but E.coli HS showed this decrease only after 12h of infection. Intestinal cell apoptosis increased after infection by all strains 24h of infection. However, the cell damage remained intense in the cells treated only with EAEC strains. EAEC 042 increased cell necrosis (p<0.05) in all evaluated periods, but the wild type strain caused damage with only at the period of 24h. All infected cells had a mRNA transcription increase of caspase 8 gene (p<0.05) in12h. NF-kB mRNA transcription increase (p<0.05) was seen in infected cells only in the period of 12h. While transcription levels of IL-8 were extremely high immediately after the infection was interrupted (0h), that was a drastic reduction at 12h after the end of infection. The wild type strain caused a reduction in cell viability linked apoptosis. However, EAEC 042 induced this decrease as also cellular necrosis. E. coli HS showed a different infection profile probably because its lack of virulence genes. AG 1mM supplementation was able to enhance cell proliferation (p<0.05) associated with apoptosis and necrosis reduction (p<0.05) in post-infected cells at the periods of 12, 24 and 48h. However, the presence of AG 1mM in infected cells did not affect the mRNA transcription low levels of c-jun and c-fos as seen after EAEC infection, and failed to block caspase 8 mRNA transcription increase (p<0.05). The IL-8 mRNA transcription temporal reduction was not associated with AG treatment in post-infected cells. Supplementation with AG had positive effects on epithelial protection against damage caused by both EAEC strains in proliferation assay and inhibition of cell death. However, since caspase 8 mRNA transcription decrease was not observed after AG treatment, AG anti-apoptosis feature could be probably related to another mechanism. Beta-carotene cell damage reversal on cell viability assay was statistical significant (p<0.05) 24 hours after infection was ended. Beta-carotene caused 48h apoptosis and necrosis (p<0.05) in wild type strain post-infected cells. Infected cells treated with beta-carotene could not block c-jun and c-fos mRNA transcription reduction and also failed to inhibit caspase 8 mRNA transcription, but beta-carotene itself increased levels of caspase 3 at the period of 12h after infection. Beta-carotene was shown to be potentially harmful to intestinal cells causing cell death probably related to its pro-oxidant effects.
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SuplementaÃÃo de alanil-glutamina em crianÃas de uma comunidade carente de Fortaleza-CE: impacto sobre a barreira intestinal e o estado nutricional infantil / Oral supplementation of alanyl-glutamine in children on a poor community at Fortaleza-CE : impact on intestinal barrier function and nutritional statusNoÃlia Leal Lima 18 December 2006 (has links)
FundaÃÃo de Amparo à Pesquisa do Estado do Cearà / IntroduÃÃo: Apesar do reconhecimento das alteraÃÃes intestinais associadas à desnutriÃÃo e dos efeitos trÃficos da alanil-glutamina (AG) na funÃÃo de barreira intestinal, medida pela taxa de excreÃÃo urinÃria de Lactulose: Manitol, ainda sÃo escassos os estudos para determinar o efeito de suplementaÃÃo oral da AG em crianÃas desnutridas. Objetivos: Examinar o efeito de suplementaÃÃo oral de AG ou placebo glicina (G) na funÃÃo de barreira intestinal e crescimento em crianÃas sob risco nutricional residentes na comunidade do Parque UniversitÃrio do Pici. MÃtodos: Ensaio clÃnico randomizado controlado em crianÃas maiores de 6 meses e menores de 8 anos de idade, com pelo menos um dos escores z para os indicadores antropomÃtricos (IAs) (peso-para-idade, estatura-para-idade e peso-para-estatura) < -1. Cento e sete crianÃas foram randomizadas, entre julho de 2003 a novembro de 2004, para receberem AG (24g/dia) ou G (25g/dia) em quantidades isonitrogÃnicas por 10 dias. A excreÃÃo urinÃria de Lactulose:Manitol foi utilizada como medida da permeabilidade intestinal e realizada nos 1 e 10 dias do protocolo de estudo. O peso e estatura das crianÃas foram coletados nos 1Â, 10Â, 30 e 120 dias do protocolo de estudo para cÃlculo dos IAs. Resultados: O percentual da excreÃÃo urinÃria de lactulose diminuiu significantemente no grupo que recebeu AG, mas nÃo no grupo que recebeu G ( p < 0,05 teste t de Student). A melhora cumulativa nos indicadores antropomÃtricos, peso-para-estatura e peso-para-idade, no 120 dia do protocolo de estudo foi significante quando realizado a anÃlise de covariÃncia no grupo que recebeu AG versus o grupo que recebeu glicina (respectivamente, p <0,04 e <0,029). Durante o perÃodo de estudo foram observados um total de vinte (19%) Eventos Adversos (EAs) na seguinte ordem de freqÃÃncia: vÃmitos (8,4%), diarrÃia (2,8%), nÃuseas (1,9%), infecÃÃo respiratÃria (1,9%), escabiose (1,9%), asma (0,9%), epistaxe (0,9%). Os EAs nÃo foram diferentes na anÃlise estatÃstica entre os grupos estudados e somente trÃs dos EAs foram considerados como SÃrios Eventos Adversos (SEAs ), dois no grupo da alanil-glutamina (1 asma e 1 diarrÃia) e um no grupo da glicina (1 diarrÃia). ConclusÃes: A suplementaÃÃo oral de AG por 10 dias melhorou a permeabilidade intestinal e o estado nutricional em crianÃas sob risco nutricional residentes em uma comunidade de Fortaleza / Introduction: In spite of the recognition of alterations in intestinal barrier function associated with malnutrition and the trophic effects of alanyl-glutamine (AG) on intestinal barrier function, measured by the rate of urinary excretion of Lactulose:Manitol, there are still few studies determining the effect of oral supplementation of AG in malnourished children. Objectives: Examine the effect of oral AG supplementation or the placebo Glycine (G) on intestinal barrier function and growth in children who are at risk for malnutrition and are residents of the University Park of Pici community. Methods: Double blind randomized study in children between 6 months and 8 years of age, with at least one of the z scores for the anthropometrical indicators (AIs) (weight-for-age, height-for-age, and weight-for-height) less than minus one. One hundred and seven children were randomized between July 2003 and November 2004, to receive AG (24 g/day) or G (25 g/day) in iso-nitrogenic quantities for 10 days. The urinary excretion of Lactulose:Mannitol was used as a measure of intestinal permeability, and was performed on the first and tenth days of the study protocol. The weight and height of the children were collected on the 1, 10, 30, and 120 days of the study protocol to calculate the AIs. Results: The percentage of urinary excretion of Lactulose decreased significantly in the group that received AG (p < 0.05 Student T test), but not in the group that received G. The cumulative improvement in the Anthropometrical Indicators, weight-for-height and weight-for-age on the 120 day of the study protocol were significant when covariant analysis was performed in the group which received AG versus the control group G (p < 0.04 and < 0.029, respectively). During the study period a total of 20 (19%) Adverse Events (AEs) were observed in the following order of frequency: vomiting (8.4%), diarrhea (2.8%), nausea (1.9%), respiratory infection (1.9%), scabies (1.9%), asthma (0.9%), epistaxis (0.9%). The AEs were not statistical different between the study groups, and only three of the AEs were considered Serious Adverse Events (SEAs), two in the AG group (1 asthma and 1 diarrhea) and one in the G group (1 diarrhea). Conclusions: The oral supplementation of AG for 10 days improved intestinal permeability and nutritional status in children at risk for malnutrition in a Fortaleza community
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Efeitos da l-alanil-glutamina sobre as concentraÃÃes in vivo de metabÃlitos em ratos submetidos à isquemia-reperfusÃo do membro pÃlvico esquerdo / Effects of L-alanyl-glutamine upon in vivo metabolites concentrations in rats subjected to hind limb ischemia followed by reperfusionMarcos AntÃnio Alves 02 December 2005 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / Instituto Dr. Josà Frota / Foram investigados os efeitos metabÃlicos da L-alanil-glutamina nas concentraÃÃes sanguÃneas e teciduais dos metabÃlitos (piruvato, lactato, glicose, acetoacetato, 3-hidroxibutirato, corpos cetÃnicos e ATP) em ratos Wistar submetidos à isquemia/reperfusÃo do membro pÃlvico. Utilizaram-se 96 ratos adultos, machos, distribuÃdos aleatoriamente em 4 grupos numericamente iguais e prÃ-tratados com soluÃÃo salina 2,0 mL (G-1 e G-3) ou L-alanil-glutamina 0,75 g Kg-1(G-2 e G-4), durante 7 dias. Uma hora apÃs a Ãltima gavagem, todos os ratos foram submetidos ao pinÃamento da artÃria ilÃaca esquerda ou operaÃÃo simulada. ApÃs 3 horas a pinÃa foi removida; nos grupos simulados realizou-se nova intervenÃÃo cirÃrgica. Amostras (mÃsculo, fÃgado, rim e sangue) foram coletadas ao final da isquemia mÃxima (T-0) e durante a reperfusÃo (1, 3 e 6h). Os metabÃlitos foram determinados por ensaio enzimÃtico e expressos como MÃdia  E.P.M. Testes nÃo paramÃtricos (Mann-Whitney e Kruskal-Wallis/Dunn) foram utilizados para a anÃlise estatÃstica. O nÃvel de significÃncia foi de p<0,05. NÃo foi evidenciada elevaÃÃo nas concentraÃÃes de lactato, piruvato e glicose durante a lesÃo de isquemia ou reperfusÃo, comparando-se os grupos tratados com soluÃÃo salina (G-1 vs. G-2). Por outro lado houve reduÃÃo nas concentraÃÃes de corpos cetÃnicos em tecido muscular no tempo de isquemia mÃxima e hiperglicemia durante o perÃodo de reperfusÃo. Houve elevaÃÃo nas concentraÃÃes hepÃticas de lactato e glicose muscular e reduÃÃo de lactato no mesmo tecido, nos ratos prÃ-tratados com o dipeptÃdeo. Observou-se ainda, nos mesmos animais, elevaÃÃo das concentraÃÃes de corpos cetÃnicos no fÃgado, no sangue, no mÃsculo e nas concentraÃÃes renais de lactato. Conclui-se, portanto, que o modelo de pinÃamento da artÃria ilÃaca esquerda promove alteraÃÃes metabÃlicas decorrentes da lesÃo de isquemia/reperfusÃo. O dipeptÃdeo L-ALA-GLN induz aumento nas concentraÃÃes hepÃticas de lactato, promove elevaÃÃo de glicose muscular e reduÃÃo de lactato no mesmo tecido indicando aumento no âturn overâ de glicose. O dipeptÃdeo causou aumento da cetogÃnese, cetonemia e captaÃÃo de corpos cetÃnicos durante a reperfusÃo, assim como hiperlactacemia e aumento nas concentraÃÃes renais de lactato. Maior atividade glicolÃtica em tecidos perifÃricos, via ativaÃÃo do ciclo malato-aspartato, levou a diminuiÃÃo da resistÃncia insulÃnica com possÃvel queda de insulinemia, com aumento da cetogÃnese. / A study has been conducted to investigate the effects of L-alanyl-glutamine upon blood and tissue concentrations of metabolites (pyruvate, lactate, glucose, acetoacetato, 3-hydroxybutyrate, ketone bodies and ATP) in Wistar rats subjected to ischemia/reperfusion of hind limb. Ninety-six adult male rats were randomized in 4 groups and pre-treated with saline 2.0 mL (G-1,G-3) or L-alanyl-glutamine solution 0.75 mgKg-1(G-2, G-4) during 7 days. One-hour after the last gavage all rats were submitted to clamping of the left iliac artery or sham operation. The clamp was removed after 3 h; sham rats were operated once more. Muscle, liver, kidney and blood samples were collected at the end of ischemia and at 1-3-6 h during reperfusion. Metabolites were submitted to enzymatic analyses. Results were expressed as Mean  S.E.M. Non-parametric tests (Mann-Whitney and Kruskal-Wallis/Dunn) were utilized for statistical analyses. P<0.05 was accepted as significant. Lactate, pyruvate and glucose concentrations did not increase during ischemia or reperfusion in rats pre-treated with saline (G-1 vs. G-2). On the other hand ketone bodies concentrations were decreased in T-0 and blood glucose was elevated during reperfusion. Liver lactate and muscle glucose were increased and lactate concentration was decreased in L-alanyl-glutamine pre-treated rats. Ketone bodies were elevated in the liver, muscle and blood and renal lactate was also elevated in the aforementioned rats. It is concluded that the model utilized in this study promotes significant metabolic alterations due to ischemia/reperfusion injury. L-Ala-Gln dipeptide induced increased hepatic lactate and muscle glucose concentrations and decreased of muscle lactate concentrations point out to increased turnover of glucose. L-Ala-Gln also induced increased ketogenesis, ketonemia and ketone bodies uptake during reperfusion along with increased lactacidemia and kidney lactate concentrations. Increased glycolytic activity in peripheral tissues via malate-aspartate shuttle activation lead to decreased insulin resistance with possible decrease in plasma insulin levels and increased ketogenesis.
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O uso prÃ-operatÃrio da l-alanilâglutamina em pacientes submetidos a revascularizaÃÃo cardÃaca com circulaÃÃo extracorporea e sua repercussÃo sobre as concentraÃÃes sÃricas de indicadores do estresse oxidativo, de mediadores inflamatÃrios, de metabolitos e sobre o controle glicemico / Pre-operative use of l-alanylâglutamine in pacients submitted to myocardial revascularization with extracorporeal bypass and its repercussions on blood plasma metabolites concentrations of oxidative stress, inflammatory mediators and glycemic controlMiguel Nasser Hissa 11 December 2008 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Estudos recentes tem apontado um efeito deletÃrio da hiperglicemia persistente em pacientes submetidos a cirurgia cardÃaca. O controle glicemico estrito abaixo de 110 mg/dl
com insulina tem demonstrado exercer um efeito antiinflamatÃrio em pacientes crÃticos,melhorando o prognostico da doenÃa. A glutamina, um aminoÃcido condicionalmente essencial durante o estresse, promove a utilizacao de glicose e aumenta a sensibilidade a insulina em pacientes criticos. Objetivou-se, no presente trabalho, estudar os efeitos de doses nutracÃuticas de L-alanil-glutamina (L-Ala-Gln) administrada no perÃodo prÃ-operatÃrio, associada ao uso intra e pÃs-operatÃrio da infusÃo de insulina. Vinte e dois pacientes adultos (idade media: 63,4 anos), candidatos a cirurgia de revascularizacao do miocÃrdio com circulaÃÃo extracorporea (CEC), foram randomizados em 2 grupos: Grupo salina (GS) e Grupo L-Ala-Gln (GG). Receberam por via endovenosa uma infusÃo de 1.000 ml de soluÃÃo salina (GS) ou 250ml de uma soluÃÃo de L-Ala-Gln a 20% diluÃda em 750 ml de soro fisiolÃgico, nas 3 horas que precederam a intervenÃÃo cirÃrgica. A insulina foi administrada ininterruptamente, durante a realizacao do procedimento cirÃrgico, a ambos os grupos. Amostras de sangue foram coletadas antes e apos a infusÃo da soluÃÃo salina ou da L-Ala-Gln [tempo basal (T-0) e pre-operatorio (T-1) respectivamente]; antes e apos a circulaÃÃo extracorporea (CEC) e no final do perÃodo operatÃrio (T-2); e 12 e 24 horas no perÃodo pÃs-operatÃrio (T3). Foram analisadas as seguintes variÃveis: Insulina, peptÃdeo C, creatinofosfoquinase (CPK), lactato desidrogenase (LDH), ProteÃna C reativa ultra-sensÃvel (PCR), IL-1, IL-6, IL-10, TN-, metabolitos (lactato, piruvato, acetoacetato e 3-hidroxibutirato), substancias reativas ao acido tiobarbiturico (TBARS), glutationa reduzida (GSH) e estado antioxidante total (TAS). AtravÃs da punÃÃo digital, amostras de sangue capilar foram coletadas, para analise da glicemia, nos periodos T-0, T-1, a cada hora durante a cirurgia (T-2) e a cada 2 horas apos a cirurgia (T-3). Apesar da administraÃÃo exÃgena de insulina durante a cirurgia ter sido constante em ambos os grupos, nos pacientes do grupo GG, a insulinemia permaneceu em concentraÃÃo semelhante em todos os perÃodos, enquanto que no grupo GS elevou-se em T-2 e T-3 comparado ao valor basal (T-1) (31.9+/-28.8 Versus 6.56+/5.4, p=0.013). O aumento da concentraÃÃo plasmÃtica de glucose foi significativamente menor nos pacientes tratados com L-Ala-Gln no perÃodo intra quando comparado ao grupo controle (129.9+/-15.2 versus 158.6+/-18.6, p= 0.003). NÃo se observaram alteraÃÃes significantes nas concentraÃÃes sericas das demais variÃveis estudadas entre os dois grupos. Conclui-se que a administraÃÃo prÃ-operatÃrio de doses
nutraceuticas de L-Ala-Gln em pacientes submetidos a cirurgia cardÃaca com revascularizacao do miocÃrdio com CEC induz uma menor elevaÃÃo da glicemia concomitante a menor elevaÃÃo da insulinemia, o que ressalta o uso potencial da administracao prÃ-operatÃrio desse dipeptideo para atingir um melhor controle glicemico e
melhorar a sensibilidade a insulina. / Recent studies have pointed out the negative effects of persistent hyperglycemia in cardiac surgery patients. Tight glucose control below 110 mg/dL with insulin has been shown to exert anti-inflammatory effects in critically ill patients. Glutamine, a conditionally essential amino
acid during stress, has been shown to promote glucose utilization and to increase insulin sensitivity in trauma patients. The present study aimed to access the effects of nutraceutical doses of L-alanyl-glutamine preoperatively in a prospective, randomized, controlled, double-blind study. Twenty-two elective patients (63 Â 8 years) with coronary artery disease scheduled for coronary artery bypass grafting were randomly assigned to receive either saline 1000 ml (Group Saline, n=11) or L-alanyl-glutamine 20% (250ml) in saline to final volume 1000 ml (Group L-alanyl-glutamine, n=11). The infusions were started 3 h prior to
the operative procedure and lasted 3 hours. Blood samples were collected 3h before [Basal (T-0)], just before the beginning of the surgical procedure [Preoperative (T-1)], at the onset and at the end of the extra-corporeal perfusion (T-2), and at the end of the surgical
procedure (Intraoperative). Additional samples were colleted 12 and 24 h later (Postoperative). The following variables were analysed: Insulin, peptide C, creatine
phosphokinase (CPK), lactate deshydrogenase (LDH), high sensibility protein C (PCR), IL-1, IL-6, 1L-10, TNF-α, metabolites (lactate, pyruvate, acetoacetate, 3-hidroxibutyrate), reactive substances to thiobarbituric acid (TBARS), reduced glutathione (GSH) and total antioxidant state (TAS). Glucose level were analysed throught capillary blood sample obtained by digital
puncture in the periods T-0, T-1, every hour during surgery (T-2) and every two hours after surgery (T-3). Despite the exogenous insulin infusion rate to be constant in both groups during the operation, insulinemia was kept at similar concentrations at all periods studied in
patients who received the dipeptide. On the other hand, control patients increased their insulinemia during the intra (T-2) and post-operative period (T-3) as compared to basal values (T-0) (31.9+/-28.8 Versus 6.56+/-5.4, p=0.013). Glucose increasing plasma concentrations were significantly decreased in L-alanyl-glutamine treated patients during the intraoperative period as compared to control patients (129.9+/-15.2 versus 158.6+/-18.6,
p= 0.003). No significant difference were observed between the two groups on plasma concentration of others variables studied. In conclusion, the infusion of nutraceutical doses of L-alanyl-glutamine prior to operative period in patients submitted to coronary artery bypass grafting with extracorporeal perfusion, reduce the glicemic surge compared to control patients, without increasing insulin plasma concentrations as compared to their basal values
This prospective study highlights the potential use of preoperative L-alanyl-glutamine administration in heart surgery patients to attain glucose control and to improve insulin sensitivity
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AlteraÃÃes metabolicas na isquemia e reperfusao da medula espinhal em ratos pre-tratados com l-alanil-glutamina / Metabolic alterations in isquemia and reperfusÃo of the spinal marrow in rats prÃ-tratados with l-alanil-glutaminaSonia Elizabeth Lopez Carrillo 18 December 2003 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / nÃo hà / Foram investigados os efeitos do prÃ-tratamento com l-alanil-glutamina (L-Ala-Gln) sobre as concentraÃÃes de glicose, piruvato, lactato e ATP na medula espinhal e sangue em ratos submetidos à isquemia/reperfusÃo medular. Utilizaram-se 72 ratos Wistar adultos, machos, distribuÃdos em dois grupos, numericamente iguais e prÃ-tratados com soluÃÃo salina (2,0 ml) ou soluÃÃo de L-Ala-Gln a 20% (0,75g/Kg peso) ApÃs 30 minutos os ratos de cada grupo foram aleatoriamente distribuÃdos em dois subgrupos (n=18). Os ratos prÃ-tratados com soluÃÃo salina (n=18) foram submetidos ao trauma cirÃrgico (G1) ou ao trauma seguido de pinÃamento da aorta abdominal infra-diafragmÃtica durante 30 minutos (G2), seguido por 10 ou 20 minutos de reperfusÃo Os animais prÃ-tratados com L-Ala-Gln foram submetidos aos mesmos procedimentos. Amostras (medula espinhal e sangue arterial) foram coletadas ao tÃrmino de perÃodo de isquemia e 10/20 minutos mais tarde. Os metabÃlitos foram determinados por ensaio enzimÃtico e expressos como MÃdia  E.P.M. Os testes âtâ de Student ou Mann-Whitney foram utilizados nas anÃlises estatÃsticas. O nÃvel de significÃncia foi de p<0,05. O trauma cirÃrgico seguido de isquemia/reperfusÃo (G2) nÃo induziu alteraÃÃes nas concentraÃÃes de glicose e lactato no sangue ou na medula dos animais prÃ-tratados com soluÃÃo salina, comparados ao grupo G1. Entretanto, a concentraÃÃo de piruvato medular reduziu-se significativamente aos 20 minutos de reperfusÃo, na medula no G2 e nos ratos prÃ-tratados com L-Ala-Gln (G3), comparados ao grupo G1. As concentraÃÃes de ATP reduziram-se significativamente no grupo G4, refletindo um maior consumo para a produÃÃo de energia. As concentraÃÃes de lactato aumentaram significativamente durante a reperfusÃo nos ratos prÃ-tratados com L-Ala-Gln, possivelmente por uma maior conversÃo de piruvato a lactato. Conclui-se que o modelo utilizado nÃo foi eficiente na produÃÃo de uma isquemia medular importante. Por outro lado, o prÃ-tratamento com L-Ala-Gln na vigÃncia do aumento das concentraÃÃes de lactato no sangue e na medula pode ser devido à glicÃlise aumentada, possivelmente secundÃria a maior disponibilidade de glutamato, produzindo ativaÃÃo da lanÃadeira malato-aspartato / A study has been conducted to investigate the effects of L-alanyl-glutamine (L-Ala-Gln) upon blood and tissue (spinal cord) concentrations of glucose, pyruvate, lactate and ATP in rats subjected to spinal cord ischemia/reperfusion. Seventy-two male Wistar rats distributed in 2 equal groups received either saline 2.0 ml or 20% solution of L-Ala-Gln (0.75g/Kg). Thirty minutes later rats of each group were randomized in two subgroups (n=18) and subjected to surgical trauma (G1) or to surgical trauma and infradiafragmatic aortic clamping for 30 minutes (G2), followed by 10 or 20 minutes of reperfusion. L-Ala-Gln treated rats were subjected to the same procedures (G3 and G4, respectively). Arterial blood and spinal cord samples were collected and the end of ischemia and 10/20 minutes later. Metabolites were submitted to enzymatic analyses. Results were expressed as Mean  S.E.M. Studentâs âtâ and Mann-Whitney tests were utilized for statistical analyses. P<0.05 was accepted as significant. Blood and spinal cord glucose and lactate were not different in G1 and G2 rats. However, spinal cord pyruvate concentrations decreased significantly after 20 minutes of reperfusion in L-Ala-Gln treated rats (G3) compared with G1. ATP concentrations decreased significantly in G4 rats, reflecting an increased utilization for energy production. Lactate concentrations were also increased during reperfusion in ischemic L-Ala-Gln treated rats (G4) possibly due to an increased turnover of pyruvate to lactate. It is concluded that the model utilized in this study did not induce an important spinal cord ischemia. Increased blood and spinal cord lactate concentrations could be related to enhanced glycolysis possibly secondary to increased glutamate availability leading to malate-aspartate shuttle activation
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