A gender difference in absolute muscle strength is well documented. The extent to which quantitative (fiber area and number) and qualitative (specific tension) differences in muscle contribute to this is not well understood. The purpose of this study was to examine a variety of muscle characteristics in the biceps brachii and vastus lateralis in a sample of males (n=8) and females (n=8) with a wide range of training histories. Measurements included motor unit number, size and activation, and voluntary strength of the elbow flexors and knee extensors. Fiber characteristics were determined from needle biopsies and muscle areas by computerized tomographical scanning. Females were approximately 52% and 66% as strong as the males in the upper and lower body respectively. A significant (p ≤ .05) correlation was found between strength and muscle cross-sectional area. Females had 45, 41, 30 and 25% smaller muscle cross-sectional areas for the biceps brachii, total elbow flexors, vastus lateralis and total knee extensors respectively (p ≤ .01). No significant gender difference was found in the strength to cross-sectional area ratio for elbow flexion and knee extension. Males had significantly larger type I fiber areas (4597 vs. 3483 um² ) and mean fiber areas (6632 vs. 3963 um² ) than females in biceps brachii (p ≤ .05) and significantly larger type II fiber areas (7700 vs. 4040 um²) and mean fiber areas (7070 vs. 4290 um²) in the vastus lateralis (p ≤ .05). The difference in type II fiber area in the biceps brachii was not statistically significant despite the fact that these fibers were almost twice as large in the males as in the females (8207 vs. 4306 um²). No significant gender difference was found in biceps fiber number (180,620 vs. 156,872) or muscle area to fiber area ratio in the vastus lateralis (451,468 vs. 465,007). No significant gender differences were found in any of the motor unit characteristics. The results indicate that the primary determinant of the greater muscle strength of males is their larger mean fiber areas which results in greater muscle cross-sectional areas. / Thesis / Master of Science (MSc)

Made available in DSpace on 2014-06-11T19:27:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-02Bitstream added on 2014-06-13T19:14:30Z : No. of bitstreams: 1 rino_as_me_botfmvz.pdf: 1140459 bytes, checksum: 5597016d559daa886389f4ed9c58c88b (MD5) / Universidade Estadual Paulista (UNESP) / As fibras musculares esqueléticas são entidades versáteis, capazes de alterar seus fenótipos de acordo com a demanda energética. Para avaliar os efeitos do exercício de enduro no músculo esquelético, foram utilizados neste estudo 36 equinos da raça Puro Sangue Árabe divididos em dois grupos: treinados e não treinados para enduro. Foram obtidos fragmentos musculares da região profunda do músculo glúteo médio e processados para técnicas histoquímicas e imunoistoquímica, utilizando-se anticorpos específicos contra isoformas de cadeia pesada de miosina (MyHC) lenta e rápida. As fibras identificadas pela histoquímica e imunoistoquímica foram analisadas uma a uma. Determinou-se a porcentagem dos diferentes tipos de fibras musculares, e avaliou-se que, a porcentagem das fibras do tipo IIA foi significativamente mais alta do que a porcentagem das fibras dos tipos I e IIX no grupo não treinado (P<0,05). Em contra partida, a porcentagem das fibras do tipo I foi significativamente mais alta do que a porcentagem das fibras dos tipo IIA e IIX no grupo treinado (P<0,05). Também foram analisados, a média da área de corte transversal e o menor diâmetro da fibra e observou-se que, a média de corte transversal das fibras do tipo IIX foi significativamente maior comparada à média de corte de transversal das fibras dos tipos I e IIA em ambos os grupos. Em conclusão pode-se afirmar que, o exercício de enduro em equinos aumenta a população das fibras de contração lenta, em detrimento da população de fibras de contração rápida / The skeletal muscle fibers are versatile entities capable to change their phonotype according to energy demand. To evaluate the effects of exercise over equine skeletal muscle in this study, 36 Arabian horses divided in 2 groups trained and untrained for endurance were used. The samples was obtained from de deep region of the gluteus medius muscle and processed for histochemistry and immunohistochemistry using specific monoclonal antibodies to selected fast and slow isoforms myosin heavy chain (MyHC). The histochemical and immunohistochemical categorization of the muscle fiber types were compared fiber by fiber. It was analyzed the percentage of different fiber types where, in the untrained group, the percentage of the fiber type IIA was higher significantly than the percentage of fiber types I and IIX (P<0.05). Unlike, the group trained showed a higher proportion of fiber type I than the fiber type IIX (P<0.05). The cross section area and lesser fiber diameter were also analyzed, and showed that, CSA of fiber type IIX was higher significantly than fibers I and IIA (P<0.05) in both groups. In conclusion, endurance exercise in equines increase the population of slow-twitch fibers in detriment of fast-twitch fibers

Orientador: Rogério Martins Amorim / Banca: Marcos Jun Watanabe / Banca: Maria Verônica de Souza / Resumo: As fibras musculares esqueléticas são entidades versáteis, capazes de alterar seus fenótipos de acordo com a demanda energética. Para avaliar os efeitos do exercício de enduro no músculo esquelético, foram utilizados neste estudo 36 equinos da raça Puro Sangue Árabe divididos em dois grupos: treinados e não treinados para enduro. Foram obtidos fragmentos musculares da região profunda do músculo glúteo médio e processados para técnicas histoquímicas e imunoistoquímica, utilizando-se anticorpos específicos contra isoformas de cadeia pesada de miosina (MyHC) lenta e rápida. As fibras identificadas pela histoquímica e imunoistoquímica foram analisadas uma a uma. Determinou-se a porcentagem dos diferentes tipos de fibras musculares, e avaliou-se que, a porcentagem das fibras do tipo IIA foi significativamente mais alta do que a porcentagem das fibras dos tipos I e IIX no grupo não treinado (P<0,05). Em contra partida, a porcentagem das fibras do tipo I foi significativamente mais alta do que a porcentagem das fibras dos tipo IIA e IIX no grupo treinado (P<0,05). Também foram analisados, a média da área de corte transversal e o menor diâmetro da fibra e observou-se que, a média de corte transversal das fibras do tipo IIX foi significativamente maior comparada à média de corte de transversal das fibras dos tipos I e IIA em ambos os grupos. Em conclusão pode-se afirmar que, o exercício de enduro em equinos aumenta a população das fibras de contração lenta, em detrimento da população de fibras de contração rápida / Abstract: The skeletal muscle fibers are versatile entities capable to change their phonotype according to energy demand. To evaluate the effects of exercise over equine skeletal muscle in this study, 36 Arabian horses divided in 2 groups trained and untrained for endurance were used. The samples was obtained from de deep region of the gluteus medius muscle and processed for histochemistry and immunohistochemistry using specific monoclonal antibodies to selected fast and slow isoforms myosin heavy chain (MyHC). The histochemical and immunohistochemical categorization of the muscle fiber types were compared fiber by fiber. It was analyzed the percentage of different fiber types where, in the untrained group, the percentage of the fiber type IIA was higher significantly than the percentage of fiber types I and IIX (P<0.05). Unlike, the group trained showed a higher proportion of fiber type I than the fiber type IIX (P<0.05). The cross section area and lesser fiber diameter were also analyzed, and showed that, CSA of fiber type IIX was higher significantly than fibers I and IIA (P<0.05) in both groups. In conclusion, endurance exercise in equines increase the population of slow-twitch fibers in detriment of fast-twitch fibers / Mestre

Resumo: Objetivos: avaliar as alterações morfológicas das fibras musculares estriadas tipos I e II da uretra de ratas prenhes diabéticas submetidas à cesárea. Métodos: Foram avaliadas 20 ratas Wistar distribuídas em quatro grupos: virgem, prenhe, diabético virgem e prenhe diabético. Os três primeiros grupos foram estudados para servir como controle do grupo principal, o prenhe diabético. O diabete foi induzido com streptozotocin na dose de 40mg/kg de peso corpóreo. O critério de inclusão foi uma glicemia acima de 200mg/dL. No final do experimento, as ratas foram anestesiadas e eutanasiadas para realização da laparotomia exploratória. A vagina e a uretra foram retiradas em monobloco, congeladas em nitrogênio líquido e mantidas a -80°C. O bloco foi submetido a cortes em criostato (6 μm de espessura). As lâminas foram coradas por H&E e utilizados anticorpos anti-miosina lenta e rápida para tipagem das fibras. Foi realizada análise morfológica e semi-quantitativa dos quatro grupos. Resultados: O músculo estriado uretral do grupo prenhe diabético apresentou: adelgaçamento, atrofia, desorganização e rompimento associado à perda de localização anatômica normal das fibras rápidas e lentas e diminuição na proporção de fibras rápidas. Conclusões: Este estudo sugere que o binômio diabete e prenhez danificou o músculo estriado uretral e alterou a composição e a distribuição das fibras tipo I e II . / Abstract: Urinary incontinence (UI) in women is defined as any involuntary urine loss. It is a frequent condition of high economic cost to the government that also results in women's physical, psychological and social damage and impaired quality of life. Various risk factors are involved in UI development; however, association with Diabetes mellitus (DM) is of great interest at present. DM affects multiple organ systems, including the urinary system in approximately 52% of diabetic patients and in those showing only hyperglycemia; however, the association between gestational DM and UI has not been fully explained. Health care professionals must be attentive to this new parameter and attempt to analyze it in more detail so that prophylactic and therapeutic measures can be established. It is necessary to delineate the chronology of the relationship between gestational Diabetes mellitus and vesical complications, the relationship between controlled diabetes and the incidence of incontinence as well as effective treatment modalities for diabetic patients with symptoms in the lower urinary tract. / Orientador: Marilza Vieira Cunha Rudge / Coorientador: Angélica Mércia Pascon Barbosa / Coorientador: Selma Maria Michelin Matheus / Banca: Débora Cristina Damasceno / Banca: Jorge Milhen Haddad / Mestre

Made available in DSpace on 2014-06-11T19:29:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T18:39:54Z : No. of bitstreams: 1 marini_g_me_botfm.pdf: 541869 bytes, checksum: 5d00927490e16293300df917e946209a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivos: avaliar as alterações morfológicas das fibras musculares estriadas tipos I e II da uretra de ratas prenhes diabéticas submetidas à cesárea. Métodos: Foram avaliadas 20 ratas Wistar distribuídas em quatro grupos: virgem, prenhe, diabético virgem e prenhe diabético. Os três primeiros grupos foram estudados para servir como controle do grupo principal, o prenhe diabético. O diabete foi induzido com streptozotocin na dose de 40mg/kg de peso corpóreo. O critério de inclusão foi uma glicemia acima de 200mg/dL. No final do experimento, as ratas foram anestesiadas e eutanasiadas para realização da laparotomia exploratória. A vagina e a uretra foram retiradas em monobloco, congeladas em nitrogênio líquido e mantidas a -80°C. O bloco foi submetido a cortes em criostato (6 μm de espessura). As lâminas foram coradas por H&E e utilizados anticorpos anti-miosina lenta e rápida para tipagem das fibras. Foi realizada análise morfológica e semi-quantitativa dos quatro grupos. Resultados: O músculo estriado uretral do grupo prenhe diabético apresentou: adelgaçamento, atrofia, desorganização e rompimento associado à perda de localização anatômica normal das fibras rápidas e lentas e diminuição na proporção de fibras rápidas. Conclusões: Este estudo sugere que o binômio diabete e prenhez danificou o músculo estriado uretral e alterou a composição e a distribuição das fibras tipo I e II . / Urinary incontinence (UI) in women is defined as any involuntary urine loss. It is a frequent condition of high economic cost to the government that also results in women’s physical, psychological and social damage and impaired quality of life. Various risk factors are involved in UI development; however, association with Diabetes mellitus (DM) is of great interest at present. DM affects multiple organ systems, including the urinary system in approximately 52% of diabetic patients and in those showing only hyperglycemia; however, the association between gestational DM and UI has not been fully explained. Health care professionals must be attentive to this new parameter and attempt to analyze it in more detail so that prophylactic and therapeutic measures can be established. It is necessary to delineate the chronology of the relationship between gestational Diabetes mellitus and vesical complications, the relationship between controlled diabetes and the incidence of incontinence as well as effective treatment modalities for diabetic patients with symptoms in the lower urinary tract.

Background. Human head and neck muscles have a special morphology and fiber type composition, different from limb and trunk muscles. Recent studies show that human muscles in palate differ from limb by having a unique cytoarchitecture. A subgroup of muscle fibers lacked cytoskeletal protein desmin and C-terminus of dystrophin molecule. These proteins are considered ubiquitous in human muscles and their absence are only reported in genetic muscular disorders. Aim. In this study, we intend to explore if other head and neck muscles have muscle fibers with absence of the cytoskeletal protein desmin. Methods. Twenty-eight different head and neck muscle samples were acquired post-mortem from a female subject (34 years) and uvula and palatopharyngeus muscles were acquired from additional five subjects (two males, three females, mean age 54 years). For comparison, autopsies and biopsies from two limb muscles of healthy subjects were acquired. The muscles were analyzed for cytoskeletal intermediate filament protein desmin with immunohistochemical methods. Results. Our findings revealed that while all limb muscles showed immunoreaction for the antibodies directed against the protein desmin, a subpopulation of head and neck muscle fibers lacked or had a faint immunoreaction for desmin. The highest proportion of muscle fibers lacking desmin were observed in the laryngeal (22.6%) and infrahyoid (19.1%) muscle groups, while the lowest proportions were found among jaw muscles (mean 0.7%). Conclusions. The result shows that head and neck muscles in general have a unique cytoskeletal build-up compared to limb muscles highlighting a functional evolutionary adaptation of these muscles.

No description available.

The SH3 and cysteine rich domain 3 (Stac3) gene is expressed specifically in skeletal muscle and essential for skeletal muscle contraction and postnatal life in mice. In this dissertation project, I conducted two studies to further understand the role of STAC3 in skeletal muscle development, growth, and contraction. In the first study, I compared the contractile responses of hindlimb muscles of Stac3 knockout and control mice to electrical stimulation, high [K+]-induced membrane depolarization, and caffeine and 4-chloro-m-cresol (4-CMC) activation of ryanodine receptor (RyR). Frequent electrostimulation-, high [K+]-, 4-CMC- and caffeine-induced maximal tensions in Stac3-deleted muscles were approximately 20%, 29%, 58% and 55% of those in control muscles, respectively. 4-CMC- and caffeine-induced increases in intracellular calcium were not different between Stac3-deleted and control myotubes. Myosin-ATPase and NADH-tetrazolium reductase staining as well as gene expression analyses revealed that Stac3-deleted hindlimb muscles contained more slow type-like fibers than control muscles. These data together confirm a role of STAC3 in EC coupling but also suggest that defective EC coupling is only partially responsible for the significantly reduced contractility in Stac3-deleted hindlimb muscles. In the second study, I determined the potential role of STAC3 in postnatal skeletal muscle growth, fiber composition, and contraction by disrupting Stac3 gene expression in postnatal mice through the Flp-FRT and tamoxifen-inducible Cre-loxP systems. Postnatal Stac3 deletion inhibited body and limb muscle mass gains. Histological staining and gene expression analyses revealed that postnatal Stac3 deletion decreased the size of myofibers and increased the percentage of myofibers containing centralized nuclei without affecting the total myofiber number. Postnatal Stac3 deletion decreased limb muscle strength. Postnatal Stac3 deletion reduced electrostimulation- but not caffeine-induced maximal force output in limb muscles. Similarly, postnatal Stac3 deletion reduced electrostimulation- but not caffeine-induced calcium release from the sarcoplasmic reticulum. These results demonstrate that STAC3 is important to myofiber hypertrophy, myofiber type composition, contraction, and EC coupling in postnatal skeletal muscle. / Ph. D.

Postnatal skeletal muscle growth occurs through myonuclear accretion and high protein turnover rate. While fiber type composition of the muscle could affect protein turnover rate, less is known about how fiber type influences the regulation of protein synthesis and degradation signaling pathways. Thus, the hypothesis of this work was that variation in fiber type composition will differentially affect the regulation of signaling pathways related to protein turnover in skeletal muscle hypertrophy in growing pigs. Downregulated protein synthesis signaling and reduced expression of type II MyHC isoforms have been reported in skeletal muscles of low birth weight (LBWT) neonatal pigs. Therefore, we sought to determine whether these changes are sustained until weaning and would explain the reduction in LBWT pig growth compared to their normal birth weight (NBWT) sibling at weaning. Another objective was to determine whether the regulation of protein turnover signaling pathways are correlated to fiber type differences in skeletal muscles. Our data suggest that the longissimus dorsi (LD, glycolytic) muscle of LBWT pigs experienced compensatory growth while the soleus (oxidative) remained proportionally smaller. Growth of the LD was accompanied by upregulation of translation initiation. Additionally, there was no difference in expression of MyHC isoforms between NBWT and LBWT pigs. These data suggest the rapid growth of the LD of LBWT pigs may be attributed to an upregulation of protein synthesis signaling and occurred only in glycolytic muscles. A caveat in LBWT pig model is that the reduction in type II MyHC at birth is not the only factor that could influence muscle growth, and that other factors may have confounded our results. This is why we aimed to use β-adrenergic agonist as a means to induce a shift fiber type in muscles to a more glycolytic phenotype. Our objective was to determine the influence of the β-adrenergic agonist Ractopamine (RAC) induced slow-to-fast fiber type transformation on the regulation of protein synthesis and degradation pathways. Although supplementation improved translational capacity, enhanced S6K1 phosphorylation, and reduced the abundance of calcium-dependent proteases, RAC feeding had no effect on body or muscle weights. These results suggest that a fiber type transformation without other physiological influences does not alter protein turnover signaling in favor of hypertrophy in growing pigs. / Master of Science / Skeletal muscles grow by increasing the amount of protein contained within them. The amount of protein deposited is determined by the net balance between the rates at which proteins are synthesized and degraded. However, not all skeletal muscles grow at the same rate. One factor that is thought to influence protein synthesis and degradation rates is the types of muscle fibers that are present within a muscle. These fibers can display a range of contractile and metabolic characteristics, from slow-twitch oxidative fibers to fast-twitch glycolytic fibers. In the presented studies, we sought to determine whether changes in fiber type composition result in difference to the signaling pathways the regulate protein synthesis and degradation, ultimately leading to differences in the muscle growth of young pigs. We have previously shown reduced activation of the protein synthesis pathway in the skeletal muscle of low birth weight (LBWT) newborn pigs. These pigs also had lower expression of glycolytic fibers. In experiment 1, we aimed to compare the signaling pathways regulating protein synthesis and degradation in LBWT and normal birth weight (NBWT) pigs at weaning. We also sought to determine if the regulation of these signaling pathways changed between muscles with differing fiber type compositions. The glycolytic longissimus dorsi (LD) muscle of LBWT pigs grew rapidly between birth and weaning whereas the highly oxidative soleus did not. In addition, the LD of LBWT pigs had greater protein synthesis signaling and similar expression of muscle fibers compared with NBWT pigs, suggesting the improvement in protein synthesis signaling of LBWT pigs between birth and weaning may be related to a shift in fiber type. In experiment 2, we used a compound called ractopamine hydrochloride (RAC) to promote a slow-to-fast fiber type switch in the muscle of young pigs. With this study, we sought to determine the effect of this fiber type transformation, without the influence of birth weight, on the regulation of protein synthesis and degradation pathways. Although RAC-fed pigs showed some minor changes that could improve protein synthesis and decrease protein degradation, RAC feeding had no observable effect on body weight or muscle growth. These results suggest that a fiber type transformation alone is not enough to promote muscle growth in growing pigs.

A ractopamina (Rac) tem sido utilizada durante a gestação de fêmeas suínas gestantes, com objetivo de melhorar o aporte nutricional ao feto, sendo considerada como repartidor de nutrientes, promovendo a lipólise e a retenção de nitrogênio, e a síntese proteica. O aumento no fluxo de nutrientes pode apresentar impactos positivos na condição corporal da fêmea gestante e o desenvolvimento do feto. O presente trabalho avaliou os efeitos da inclusão de 10 e 20 mg/kg de ractopamina na ração de fêmeas suínas gestantes, entre os dias 25 a 50 da gestação, sobre o desempenho produtivo, reprodutivo, parâmetros fisiológicos, hemograma e bioquímica sanguínea das fêmeas e sobre a vitalidade, hemograma, bioquímica sanguínea, número de fibras musculares no músculo semitendinosus e estado metabólico dos leitões. Foram utilizadas 41 fêmeas de linhagem comercial híbrida, DB 90 (DB-Genética Suína, Patos de Minas, MG), divididas de acordo com a ordem de parto em 3 tratamentos: Controle: sem ractopamina; Rac10: 10 mg/kg de ractopamina; Rac20: 20 mg/kg de ractopamina. O tratamento foi administrado diariamente via top dressed durante os 25 a 50 dias de gestação. As avaliações e as coletas de amostras foram realizadas nos 25, 37, 50, 107 dias de gestação e nos 1, 7, 14 e 21 dias da lactação. Para a avaliação da vitalidade foi utilizado o teste de pontuação Apgar modificado por Motta-Rojas (2005). A suplementação de ractopamina durante a gestação não influenciou o desempenho reprodutivo das fêmeas, dos leitões até o desmame e no número de fibras musculares no músculo semitendinosus ao nascimento. Houve um aumento na frequência cardíaca e de leitões com vitalidade baixa nas fêmeas suplementadas com Rac. Houve alterações no hemograma, bioquímica sanguínea das fêmeas, mas não nos leitões. Os resultados obtidos a partir das análises do hemograma e bioquímica sanguínea indicam ação da ractopamina sobre o metabolismo lipídico e proteico das fêmeas sem reflexos importantes nos valores observados nos leitões. O presente trabalho concluiu que a suplementação de Rac durante os 25 a 50 dias da gestação não influencia negativamente no metabolismo das fêmeas e sua progênie até o desmame. Por outro lado, a suplementação de Rac aumenta a frequência cardíaca sem aumento de frequência respiratória e temperatura retal das fêmeas, no entanto, pode ser considerado ainda dentro dos parâmetros fisiológicos normais durante a gestação. O aumento no número de leitões de vitalidade baixa 10 pode estar relacionado a um aumento numérico do peso ao nascimento dos leitões. Contudo, a suplementação de Rac durante os 25 50 dias da gestação não influencia negativamente no desempenho produtivo das fêmeas e sua progênie até o desmame. / The ractopamine (Rac) has been used in pregnant sows, aiming to improve the nutritional contribution to the fetus, being considered as nutrient delivery, promoting lipolysis and retention of nitrogen and protein synthesis. Increased nutrient flow may have positive impacts on the body condition of sows and fetal development. The present study evaluated the effects of the inclusion of 10 and 20 mg / kg of ractopamine in the diet sows from 25 to 50 days of pregnancy. Assessing possible effects on productive, reproductive performance, physiological parameters, complete blood count and blood serum biochemistry of females and on vitality, complete blood count, blood serum biochemistry, number of muscle fibers in the semitendinosus muscle and metabolic status of their piglets. Forty one sows of hybrid commercial line, DB 90 (DB-Genetics Swine, Patos de Minas, Minas Gerais),were used and divided according to the order of parity in 3 treatments: Control: No ractopamine; Rac10: 10 mg / kg ractopamine; Rac20: 20 mg / kg ractopamine. The treatment was administered daily via top dressed during the 25 to 50 days of gestation. The evaluations and sample collections were performed at 25, 37, 50, 107 days of gestation and at 1, 7, 14 and 21 days of lactation. Assessment of vitality was used the apgar score test modified by Motta-Rojas (2005). The supplementation of ractopamine during gestation did not influence the female reproductive performance, piglets performance until weaning and muscle fibers in the semitendinosus muscle at birth. There was an increase in heart rate and low vitality in females supplemented with Rac. There were alterations in the complete blood count, blood serum biochemistry of the females, but not in the piglets. The results obtained from the hemogram and blood biochemistry analysis indicate the action of ractopamine on the lipid and protein metabolism of the females without significant reflexes in the piglets values. The present study concluded that the supplementation of Rac during the 25 to 50 days of gestation does not negatively influence the metabolism of the females and their progeny until weaning. On the other hand, supplementation of Rac increases the heart rate without increasing respiratory rate and rectal temperature of the females, however, this can still be considered within the normal physiological parameters during gestation. The increase in the numbers of low-vitality piglets may be related to a numerical increase in the birth weight of the piglets. However, Rac 12 supplementation during the 25-50 days of gestation does not negatively influence the productive performance of the females and their progeny until weaning.