The study was conducted to determine the effect of pre-slaughter stress of pigs on the levels of cortisol, creatine kinase (CK) and their subsequent relationship with pork quality. From our knowledge, there is paucity of information on transportation, lairage duration and sex effects on saliva cortisol and its relation with serum cortisol, urine cortisol and other meat quality traits. Stage one of the study assessed the effect of sex and time to slaughter (transport and lairage duration) on the levels of cortisol and CK in crossbred pigs. The second stage of the study evaluated the effect of sex and lairage duration on pork quality. The trials comprised of 60 22-weeks old commercial crossbred pigs [(30 boars vs. 30 gilts) with an average body weight of 76.9kg for gilts and 78.3kg for boars. Thirty pigs (15 Boars vs. 15 Gilts) were slaughtered on arrival after a 120km road journey and the other 30, after travelling the same road and distance, were slaughtered after having been in the lairage for 20 hours. Saliva samples were obtained during three time periods: between 07:00-10:00 on the day before the journey, on arrival at the abattoir and after lairage. Levels of cortisol in serum and urine and CK in serum samples collected at slaughter were determined. The samples (saliva and serum) were centrifuged at 20oC for 10 min at 3550 x g and stored at -20oC in separate vials until analysis. Pork quality was assessed using muscle pH, colour, thawing and cooking losses and Warner-Bratzler Shear Force. Correlations between cortisol levels in saliva, serum and urine and meat quality were assessed. The effect of sex and time to slaughter on saliva cortisol was significant. Statistical analysis showed significant interaction of sex by time to slaughter on serum cortisol. It was only the effect of sex that demonstrated higher (P <0.05) serum creatine kinase levels in gilts. Likewise, urine cortisol was influenced (P <0.05) only by time to slaughter. Saliva cortisol after transportation (r = 0.52) was correlated (P <0.05) with urine cortisol. The study suggests that there are greater responses of the Hypothalamic-pituitary-adrenal axis following time to slaughter (transport and lairage duration) between gilts and boars. This can be used in measuring cortisol in saliva, serum and urine, and serum creatine kinase to determine stress levels in pigs. Besides the lightness (L*) colour value which was significantly lower (P <0.05) in meat from gilts than from boars, the results of this study showed no interaction or individual effect (sex or lairage duration) on pH and other colour measurements. Meat cooking loss was affected (P <0.05) by gender x lairage interaction. Effect of lairage duration (as an individual effect) on the measured meat quality traits was not significant (P <0.05). Correlation analysis showed significant (P <0.05) negative relation between baseline saliva cortisol (r = -0.40) and the pork L* value. Saliva cortisol after lairage duration (r = -0.38 and r = 0.38) was correlated (P <0.05) with pH45 and pork a* value, respectively. Serum cortisol (r = -0.35) was negatively correlated (P <0.05) with pH45. Moreover, there were negative correlations (P <0.05) between saliva cortisol after transportation (r = -0.35), saliva cortisol after lairage duration (r = -0.44), serum cortisol (r = -0.40) and meat cooking loss. The study suggests that cortisol in saliva and serum can be used to determine effect of time to slaughter (transport and lairage duration) on meat quality traits from gilts and boars. Keywords: Boars; gilts; saliva cortisol; serum cortisol; serum creatine kinase; urine cortisol.

Aim: The purpose of this study was to investigate docosahexaenoic acid (DHA) ingestion on muscle damage and inflammation during the first two weeks of a novice resistance training (RT) program. Methods: This study was a placebo-controlled, double-blind design. Forty-one healthy untrained males between the ages of 18 and 28 years consumed 2,000 mg/d of either DHA or corn oil (PCB) for 44 days including a 28 day loading period. Serum fatty acids were analyzed to determine treatment efficacy. During the 17 day training period, an acute eccentric exercise bout was implemented followed by a full-body RT regimen thrice weekly. Six fasted blood draws (days 1, 2, 4, 7, 12, and 17) during this exercise period were analyzed for creatine kinase (CK) and C-reactive protein (CRP). Maximum isometric strength (ISO) of the elbow flexors, delayed onset muscle soreness (DOMS), and range of motion (ROM) were measured on day 1 prior to exercise and also on days 2, 3, 4, 7, 12, and 17. Results: The CK response and the area under the curve (AUC) analysis for DOMS trended to decrease in the DHA group in comparison to placebo (p=0.0925 and p=0.0536, respectively). Treatment showed no effect on CRP levels. DHA supplementation significantly increased serum DHA by 380% as a proportion of total fatty acids (p<0.0001). Conclusion: This study does not demonstrate convincing benefits of DHA ingestion to recovery from a new resistance exercise program but does suggest a need for further investigation. / Master of Science

IN ENGLISH The ischemia-reperfusion (I/R) injury, which is a consequence of myocardial infarction, represents a major cause of death worldwide. One of the most effective cardioprotective interventions increasing the resistance of hearts to the I/R injury is the adaptation to a chronic hypoxia (CH). However, the molecular mechanisms of CH are still not well understood. The most important factors responsible for the I/R injury are reactive oxygen species (ROS) produced by complexes I and III within the mitochondrial electron transport chain. Potential candidates maintaining ROS at a low level are mitochondrial creatine kinase (mtCK) and two hexokinase isoforms (HK1 and HK2). These enzymes highly support the mitochondrial oxidative phosphorylation by increasing the availability of ADP for complex V of the respiratory chain. In addition, the HK binding to mitochondria inhibits binding of the pro- apoptotic protein BAX, thereby protecting cardiac cells against apoptosis. Besides the mitochondrial CK isoform, there are two cytosolic CK (CKM and CKB) present in cardiomyocytes that help to maintain energy homeostasis. Based on the known anatomical and physiological differences between the left (LV) and the right (RV) ventricles, the first study focused on the comparing ventricles in terms of the energy...

INTRODUÇÃO: A Região Metropolitana de São Paulo é a mais populosa do Brasil. A grande frota veicular contribui para uma maior concentração de poluentes atmosféricos. Diversos poluentes podem interferir na fertilidade humana, alterando os principais parâmetros seminais. Este estudo teve como objetivo avaliar a influência dos níveis atuais de poluição atmosférica de origem veicular nos parâmetros seminais em controladores de tráfego. MÉTODOS: Foram realizadas anamnese e avaliação clínica urológica (volume testicular, presença de varicocele, criptorquidia, má formações) em 62 controladores de tráfego da CET (grupo exposto) e 210 homens comprovadamente férteis do grupo de pré-vasectomia do ambulatório da urologia do HC-FMUSP (grupo controle). Os parâmetros seminais avaliados foram concentração, motilidade (quantitativa e qualitativa), morfologia pelos critérios da OMS e critério estrito de Kruger, teste para detecção de leucócitos e testes de função espermática, CK, ROS e anticorpo anti-espermatozóide. Parâmetros hormonais também foram avaliados. Avaliação de exposição à poluição foi realizada através da dispersão de poluentes registrado pela Cetesb, gerada pelo software SURFER 8.0. RESULTADOS: Os controladores de tráfego apresentaram volume testicular maior em relação ao grupo pré-vasectomia (p<0,001). Quanto aos níveis de Estradiol (p=0,119), LH (p=0,644), FSH (p=0,140) e Testosterona total (p=0,365), ambos os grupos apresentaram valores dentro da normalidade. A concentração espermática apresentou-se homogênea nos grupos (p= 0,395); os controladores de tráfego apresentaram média de 124,9 x 106/ml e os pré-vasectomia 110,1 x 106/ml. Os controladores de tráfego apresentaram motilidade quantitativa (total) reduzida (60%) em relação aos prévasectomia (65%) (p= 0,047). A motilidade qualitativa (progressiva) também se apresentou diminuída no grupo exposto (p<0,001). As morfologias espermáticas tanto pelo critério da OMS (grupo exposto = 12%; grupo controle = 20%), quanto pelo critério estrito de Kruger (grupo exposto = 3%; grupo controle = 6%) estavam significativamente diminuídas no grupo exposto em relação ao controle (p<0,001). O marcador de maturidade Creatina Quinase apresentou-se dentro da normalidade em ambos os grupos, porém maior no grupo controle (p<0,001). Anticorpos anti-espermatozóides estavam elevados nos dois grupos, porém não foi significativo (p=0,382). Radicais livres de oxigênio apresentaram-se em altas concentrações nos dois grupos, porém não foi significativo (p=0,141). CONCLUSÕES: A análise dos dados obtidos nessa pesquisa sugere que a poluição atmosférica exerce uma influência negativa sobre os parâmetros seminais motilidade e morfologia. Causa elevação dos níveis de ROS em todos os indivíduos, indicando perda da função espermática. Ainda demonstrou-se a elevação em todos os indivíduos dos níveis de anticorpos anti-espermatozóides, sugerindo que os poluentes teriam transposto a barreira hemato-testicular. O volume testicular do grupo exposto à poluição veicular apresentar-se maior em relação ao volume testicular do grupo controle nos leva a supor que isto se deva a uma reação inflamatória aos agentes poluidores. Apesar da diferença significativa na concentração de poluentes entre os grupos, uma correlação direta com parâmetros seminais não pôde ser demonstrada / Metropolitan Region of Sao Paulo is the most populous of Brazil. The huge number of vehicles contributes for a higher concentration of air pollutants. Various pollutants can interfere in human fertility, altering the main seminal parameters. The aim of this study was to evaluate the influence of air pollution of vehicular origin on seminal parameters of traffic controllers. Clinical history and urological evaluation (testicular volume, presence of varicocele, cryptorchidism, bad formations) were carried out in 62 traffic controllers (exposed group) and 210 proven fertile men from the pre-vasectomy group of urologic clinic at Hospital of Clinics University of Sao Paulo (control group). Seminal parameters evaluated were concentration, motility (quantitative and qualitative), morphology by WHO´s criteria and Kruger´s strict criteria, test for detection of leukocytes and tests of sperm function, CK, ROS and antisperm antibody. Hormonal parameters also were evaluated. Exposition to air pollution was analyzed through the dispersion of pollutants recorded by Cetesb, generated in the software SURFER 8.0. Traffic controllers presented bigger testicular volume than prevasectomy group (p<0,001). Hormonal levels were at normal range in both groups; Estradiol (p=0,119), LH (p=0,644), FSH (p=0,140) and Total Testosterone (p=0,365). Sperm concentration was homogeneous in both groups (p= 0,395); traffic controllers presented mean of 124.9x106/ml and pre vasectomy group 110.1x106/ml. The exposed group presented quantitative (total) motility (60%) diminished than control group (65%) (p=0,047). The qualitative (progressive) motility was also diminished in the exposed group (p <0,001). The sperm morphologies as by WHO´s criteria (exposed group = 12%; control group = 20%), as by Kruger´s strict criteria (exposed group = 3%; control group = 6%) were significantly diminished in the exposed group (p<0,001). The sperm maturity marker Creatine Kinase was at normal range at both groups, but higher in the control one (p<0,001). Antisperm antibodies was elevated in both groups, however it was not significant (p=0,382). ROS presented higher concentrations in both groups, however it was not significant (p=0,141). The facts presented in this study suggest that air pollution exercises negative effects on the seminal parameters motility and morphology. It causes elevation of ROS levels in all individuals, indicating loss of sperm function. It also showed, elevation of antisperm antibodies levels, suggesting that pollutants would have transposed the blood-testis barrier. The testicular volume in the exposed group was higher than the testicular volume of the control group; we can suppose that it must occur due to an inflammatory reaction against the polluting agents. Although the significant difference in pollutants concentrations between groups, no direct correlation to seminal parameters could be demonstrated

Este estudo compara quatro diferentes intensidades com o volume total similar no exercício supino. Avaliou-se a dor muscular de início tardio (DMIT), atividade de creatina quinase (CK), as concentrações sangüíneas de interleucina (IL)-1<font face=\"symbol\">b, IL-6, fator de necrose tumoral-<font face=\"symbol\">a (TNF-<font face=\"symbol\">a), prostaglandina E2 (PGE2) e o perfil hormonal. A amostra foi composta de soldados do exército brasileiro, divididos em cinco grupos: 50%-1RM, 75%-1RM, 90%-1RM, 110%-1RM e o controle. A DMIT e a atividade plasmática de CK aumentaram significativamente (P<0,05) após a sessão de exercício. A concentração de PGE2 também teve aumento significativo (P<0,05) após a sessão (P<0,05). A concentração plasmática de cortisol após 1h do término do exercício aumentou apenas no grupo 75%-1RM (p < 0,05). Esses resultados sugerem que a intensidade no exercício supino não afeta a magnitude da DMIT, marcadores de lesão muscular, inflamação e na resposta hormonal geral, desde que haja a equalização do volume total, com exceção da concentração plasmática do cortisol, grupo 75%-1RM. / This study compared four different intensities with similar total volume of a bench press exercise for muscle soreness, creatine kinase (CK) activity, interleukin (IL)-1<font face=\"symbol\">b, IL-6, tumor necrosis factor-<font face=\"symbol\">a (TNF-<font face=\"symbol\">a), prostaglandin E2 (PGE2) and hormonal concentrations in the blood. Brazilian Army male soldiers were placed into five groups: 50%-1RM, 75%-1RM, 90%-1RM, and 110%-1RM, and control that did not perform the exercise. Muscle soreness and plasma CK activity increased significantly (p<0.05) after exercise. Serum PGE2 concentration also increased significantly (p<0.05) after exercise. After one hour post exercise cortisol increased in 75%-1RM group, with this response also exceeding the other intensities (p<0.05). These results suggest that the intensity of bench press exercise does not affect the magnitude of muscle soreness and blood markers of muscle damage, inflammation and largely similar hormonal responses, which may be attributed to the equalization of total volume, exception made for the 75%-1RM group for serum cortisol concentration.

Divers stimuli tels que l'ischémie, l'hypoxie et l'exercice peuvent induire la déplétion en ATP provoquant une déregulation de l'homéostasie énergétique. Cependant, les cellules disposant de mécanismes compensatoires pour contrebalancer et compenser le déficit de l'état énergétique cellulaire. Deux enzymes clés participent à la régulation du métabolisme énergétique cellulaire. La créatine kinase (CK) peut réagir immédiatement comme transporteur d'énergie. D'autre part la protéine kinase activée par l'AMP (AMPK), régule au niveau cellulaire et du corps en entier la livraison et la consommation d'énergie. Dans ce travail de thèse, les outils de base pour realiser un criblage des cibles de l'AMPK ont d'abord été mis en place. Ce sont les protocoles multidimensionnelles pour la purification de protéines par HPLC et le criblage in vitro de cibles membranaires de l'AMPK, dont le sous-fractionnement des membranes et la separation par électrophorèse de type blue native PAGE. Différents candidats potentiels de l'AMPK ont été obtenus, et deux ont été confirmés par phosphorylation in vitro. Ensuite, une interaction entre les deux enzymes, l'AMPK et la CK, a été confirmée pour la première fois in vitro et in vivo. L'AMPK phosphoryle la créatine kinase cytosolique du cerveau (BCK) sur la serine 6 in vitro et in vivo. Cette phosphorylation a été mis en evidance à l'aide de tests de phosphorylation et d'un anticorps généré spécifique de la phospho-Ser6. Le system de double hybride en levure a montré que cette phosphorylation est acompagné par une interaction transitoire impliquant spécifiquement l'AMPK active et BCK non phosphorylé. La phosphorylation médiée par AMPK n'affecte pas l'activité enzymatique de BCK mais localise la kinase dans le réticulum endoplasmique (RE) in vivo. Le travail presente dans ce manuscript confirme une interaction entre les deux enzymes clefs dans l'homeostasis energetique. La caracherization in vitro et in vivo de la phosphorylation de la BCK par l'AMPK suggère que l'AMPK regule probablement l'associattion de BCK aux compartements subcellulaires et pas l'activité enzymatique. Cette localisation est induite par l'AMPK en cas de stress énergetique et peut soutenir des processus fortement dépendant de l'ATP dans ce microenvironnement, comme par exemple le pompage de calcium.

<p>The aims of this project were to investigate the impact of perioperative myocardial damage on morbidity and mortality after coronary artery bypass grafting (CABG), to determine whether biochemical marker levels after CABG correlate to perioperative myocardial infarct size, and to assess the long-term morbidity after CABG, in particular to determine whether women do worse.</p><p>The studies were conducted in patients who had undergone isolated, primary CABG. The correlation of postoperative cardiac marker levels to early and late survival was evaluated in 4,911 consecutive patients; this showed that elevated cardiac markers implied a highly increased risk of both early cardiac death and late death. Hospital readmission for any cause and effect of gender on the readmission rate were analysed in 7,493 patients; it was found that the risk of readmission was higher in women than in men, because of greater co-morbidity and higher age. In the same patient cohort, it was clearly demonstrated that perioperative myocardial damage increased the risk of heart failure independently, and that late mortality was greatly increased in patients readmitted for heart failure. Finally, in a prospective, clinical trial, creatine kinase MB (CK-MB) and troponin I and T levels were found to correlate to infarction mass, as quantified by magnetic resonance imaging postoperatively. The findings strongly suggested that CK-MB above five times the upper normal limit was the result of perioperative myocardial infarction.</p><p>In conclusion, perioperative myocardial damage is an important adverse event with a highly negative effect on early and late survival after CABG, and also entails an increased risk of subsequent heart failure, which markedly impairs long-term survival. Gender differences may be explained by patient characteristics and risk factors and not by female sex per se. Increases in biochemical markers after CABG correspond to the amount of perioperatively infarcted myocardium. </p>

The aims of this project were to investigate the impact of perioperative myocardial damage on morbidity and mortality after coronary artery bypass grafting (CABG), to determine whether biochemical marker levels after CABG correlate to perioperative myocardial infarct size, and to assess the long-term morbidity after CABG, in particular to determine whether women do worse. The studies were conducted in patients who had undergone isolated, primary CABG. The correlation of postoperative cardiac marker levels to early and late survival was evaluated in 4,911 consecutive patients; this showed that elevated cardiac markers implied a highly increased risk of both early cardiac death and late death. Hospital readmission for any cause and effect of gender on the readmission rate were analysed in 7,493 patients; it was found that the risk of readmission was higher in women than in men, because of greater co-morbidity and higher age. In the same patient cohort, it was clearly demonstrated that perioperative myocardial damage increased the risk of heart failure independently, and that late mortality was greatly increased in patients readmitted for heart failure. Finally, in a prospective, clinical trial, creatine kinase MB (CK-MB) and troponin I and T levels were found to correlate to infarction mass, as quantified by magnetic resonance imaging postoperatively. The findings strongly suggested that CK-MB above five times the upper normal limit was the result of perioperative myocardial infarction. In conclusion, perioperative myocardial damage is an important adverse event with a highly negative effect on early and late survival after CABG, and also entails an increased risk of subsequent heart failure, which markedly impairs long-term survival. Gender differences may be explained by patient characteristics and risk factors and not by female sex per se. Increases in biochemical markers after CABG correspond to the amount of perioperatively infarcted myocardium.

Leucine is a regulator of protein metabolism in vivo, and there is little information regarding its action on cardiac hypertrophy induced by experimental hyperthyroidism and its relationship to serum creatine kinase. The study aimed to verify the effect of leucine in cardiac hypertrophy and serum creatine kinase in rats with hyperthyroidism. 75 animals were used, divided into two large groups according to the length of the experiment, seven days Group (7D) and Group twenty-eight days (D 28), subsequently divided into five subgroups these being the control zero (C0-7 and C028 ) controls (C-7 and C-28), hormone (H-7 and H- 28), leucine (G-7 and G-28) and leucine + hormone (LH-7 and HL-28). Hyperthyroidism was induced by administration of daily 20&#956;g/100 grams of levothyroxine sodium in aqueous suspension by gavage. Leucine was supplemented by adding 5% of the amino conventional diet. Blood was collected by cardiac puncture and analyzes made in kits for TSH, T3, T4 and CK-NAC CK-MB. At the end of the experiment the heart was removed and weighed. Subsequently, the left ventricle was separated together with the interventricular septum and heavy, was also performed to measure the transverse diameter of cardiomyocytes and compared between groups. The exercise tolerance was measured by the swim test and the intensity was determined in 7% of the weight of the animal. Blood pressure and heart rate were measured using a sphygmomanometer to rats tail, 4/25T ADInstruments PowerLab equipment ® and ® software ADInstruments LabChart 7. In statistical comparison was used analysis of variance (ANOVA) and two-way post-Tukey test, considering p values <0.05. In rats treated with thyroid hormone occurs, cardiac hypertrophy with increased weight of the left ventricle, increased heart rate and elevated concentrations of CK-MB after 28 days. The association of leucine seems to modulate hormone-induced cardiac hypertrophy in this experimental model, and reduce blood concentrations of CK-NAC and CK-MB by unknown mechanisms. Thyroxine increases the swimming performance of rats after therapy for 14 and 21 days but with performance drop in 28 days. / A leucina é um regulador do metabolismo proteico in vivo, e existem poucas informações referentes à sua ação na hipertrofia cardíaca induzida pelo hipertireoidismo experimental e sua relação com a creatina quinase sérica. O estudo teve por objetivo verificar a ação da leucina na hipertrofia cardíaca e na concentração sérica de creatina quinase em ratos Wistar em hipertireoidismo. Foram utilizados 75 animais, divididos dois grandes grupos de acordo com o tempo de experimento, Grupo sete dias (7D) e Grupo vinte e oito dias (28 D), posteriormente divididos em cinco subgrupos sendo estes o controle zero (C0-7 e C028) controle (C-7 e C-28), hormônio (H-7 e H-28), leucina (L-7 e L-28) e hormônio + leucina (HL-7 e HL-28). O hipertireoidismo foi induzido administrando-se, diariamente, 20&#956;g/100 gramas de levotiroxina sódica em suspensão aquosa, por gavagem. A leucina foi suplementada adicionando-se 5% do aminoácido à ração convencional. O sangue foi coletado por punção cardíaca e as análises feitas em kits para TSH, T3, T4 CK-NAC e CK-MB. Ao final do período experimental o coração foi removido e pesado. Posteriormente, foi separado o ventrículo esquerdo juntamente com o septo interventricular e pesado, também foi realizada a medida do diâmetro transversal dos cardiomiócitos e os resultados comparados entre os grupos. A tolerância ao esforço foi medida através do teste de natação e a intensidade foi determinada em 7% do peso do animal. A pressão arterial e frequência cardíaca foram aferidas utilizando um esfignomanômetro de cauda para ratos, o equipamento PowerLab 4/25T ADInstruments® e o software LabChart 7 ADInstruments®. Na comparação estatística foi utilizada a análise de variância (ANOVA) de duas vias e pós-teste de Tukey, considerando-se significativos valores de p<0,05. Em ratos tratados com hormônio tireoidiano ocorre, hipertrofia cardíaca com aumento do peso do ventrículo esquerdo, aumento da frequência cardíaca e elevação das concentrações de CK-MB após 28 dias. A associação de leucina ao hormônio parece modular a hipertrofia cardíaca induzida neste modelo experimental, além de reduzir as concentrações sanguíneas de CK-NAC e CK-MB por mecanismos ainda desconhecidos. A tiroxina aumenta o desempenho da natação de ratos após uma terapia de 14 e 21 dias, porém com queda de performance em 28 dias. / Mestre em Ciências da Saúde

Orientador: Jaime Amaya-Farfan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-09T15:53:11Z (GMT). No. of bitstreams: 1 Carvalho_IaraRibeiro_M.pdf: 1875369 bytes, checksum: 01034f576b4ca76425fe296fed74054e (MD5) Previous issue date: 2008 / Resumo: Estudos recentes sugerem que o consumo das proteínas do soro de leite, quando parcialmente hidrolisadas, resulta em efeitos fisiológicos diferentes daqueles produzidos pelas proteínas intactas. Desse modo, o objetivo do presente trabalho foi verificar as alterações metabólicas causadas nos tecidos do estômago e coração, e na resistência à exaustão, utilizando ratos Wistar alimentados com isolado do soro de leite, ou seu proteolisado enzimático, e submetidos a exercício físico. Foram investigadas possíveis alterações na atividade enzimática da pepsina, glicogênio sintase, glicogênio fosforilase, creatina quinase e glicogênio do miocárdio e a perfusão de peptídeos através do estômago. O ensaio biológico teve duração de 42 dias, com 120 ratos divididos em 12 grupos (n=10), sendo três fontes protéicas: caseína (C), proteína hidrolisada (H), proteína intacta do soro de leite (I) e quatro tipos de atividade física: treinado (T), treinado-exausto (TX), sedentário (S), sedentário-exausto (SX), em esteira rolante, por quatro semanas. Foram observados valores mais altos na atividade da enzima creatina quinase (sem diferença significativa) nos grupos T e TX, quando esses consumiram dieta H. Em relação ao treinamento, foram encontradas maiores quantidades de glicogênio miocárdico nos animais submetidos a menor atividade física. Em relação à dieta, as concentrações de glicogênio variaram aleatoriamente. Entretanto, os animais que consumiram a dieta H exibiram menor atividade da glicogênio sintase do que aqueles que receberam dieta I, e esses também menores que a dieta C. Na enzima glicogênio fosforilase, notou-se valores maiores de atividade enzimática nos grupos de animais do grupo T em relação aos outros grupos, sendo que a dieta H mostrou resultados menores em comparação com as outras dietas. Quanto à exaustão, foram comparados os grupos H e I, sendo que os grupos que foram submetidos a treinamento prévio (TX) mostraram-se mais resistentes à exaustão do que aqueles que foram mantidos sedentários (SX). Na atividade enzimática da pepsina, os resultados entre grupos foram semelhantes, notando-se aumento no grupo sedentário que consumiu o hidrolisado, mas desaparecendo com a exaustão. Estudo da possibilidade de perfusão de peptídeos através da parede estomacal encontrou evidências de que, ao menos, um peptídeo rico em valina é detectado no perfusado externo ao cabo de duas horas. Foi observada maior quantidade de picos eletroforéticos no conteúdo do estômago dos animais dos grupos SX e TX que receberam infusão do hidrolisado e teores de aminoácidos livres mais elevados no grupo S do que nos demais. Associando os valores encontrados para aminoácidos livres com os valores de aminoácidos totais, no interior e exterior do estômago, pode se afirmar que o conteúdo de peptídeos formados no estômago, no grupo que recebeu a infusão de hidrolisado, foi superior à que recebeu o isolado. Conclui-se que ambos o tipo de atividade física e a fonte protéica da dieta podem influenciar aspectos fisiológicos, tais como a atividade da pepsina, a facilidade com que peptídeos são gerados e acumulados no órgão, sendo que alguns peptídeos podem atravessar a parede estomacal. As implicações decorrentes destes fenômenos ainda aguardam maior investigação / Abstract: Recent studies suggest that the consumption of milk whey proteins, if partially hydrolyzed, result in different physiological effect from those produced by the ingestion of the unbroken proteins. Therefore, the objective of the present work was to verify eventual metabolic alterations caused in the stomach and heart tissues of exercising Wistar rats fed an enzymatic milk whey hydrolyzate, as compared to cohorts receiving the unhydrolyzed proteins. The enzymatic activity of pepsin and those of glycogen synthase, glycogen phosphorylase, creatine kinase, as well as glycogen stores of the myocardium were thus investigated. Additionally, the perfusion of peptides through the stomach wall using capillary electrophoresis and liquid chromatography was also verified. The biological assay was conducted with 120 rats, during 42 days. The animals were divided into 12 groups (n=10), as follows: three protein sources: casein (C), protein hydrolyzate (H) and the unbroken whey protein (I), in addition to four types of physical activity: trained (T), trained-exhausted (TX), sedentary (S), sedentary-exhausted (SX) for four weeks. For creatine kinase, higher activities were observed (without significant difference) in groups T and TX, when these consumed diet H. With regard to myocardial glycogen, higher stores were found in the animals with lesser physical activity, while glycogen concentrations varied randomly in response to the diet. However, the animals that consumed diet H exhibited lower glycogen synthase activity in comparison to those that received diet I, which in turn were lower than those that received diet C. As for glycogen phosphorylase, higher values were noticed in the groups subjected to training (T) in relation to the other groups. Similarly, the animals on diet H also responded with lower activities. With regard to exhaustion time, only those groups that underwent training (TX) appeared to be more resistant to exhaustion than those that remained sedentary (SX). The enzymatic activity of pepsin did not show significant differences among groups, except for the increase of the sedentary that consumed diet H. The increase, however, disappeared when the animals were brought to exhaustion. Study of the possibility of perfusion of whey protein peptides through the stomach wall suggested that at least one peptide rich in valine promptly perfused to the external fluid. A higher number of capillary electrophoretic peaks were also observed in the stomach contents of the animals of groups SX and TX that received the hydrolyzate infusion and, by liquid chromatography, it was possible to notice that the group S stomachs had greater levels of free amino acids than the other groups. Comparing the values found for free amino acids with the total amino acids, in both the inside and outside of the stomach, it could be stated that the content of peptides formed in the stomach was considerably greater in the group infused with the hydrolyzate than with the isolate. It is concluded that chronic consumption of the whey protein hydrolyzate as the only source of protein results in enzymatic changes consistent with a more efficient physiologic state, favorable to higher physical performance, such as higher myocardial creatine kinase and lower glycogen kinase and phosphorylase activities. No significant changes in pepsin activity in the rat stomach were observed, but the readiness with which the hydrolyzate peptides accumulate and traverse the organ wall was evident. Further data to provide a better understanding of the implications of consuming prehydrolyzed proteins await investigation / Mestrado / Nutrição Experimental e Aplicada à Tecnologia de Alimentos / Mestre em Alimentos e Nutrição