Efeito da creatina sobre a remodelação do músculo estriado esquelético de ratos submetidos a treinamento físico resistido.

Introdução: Há evidências que a creatina associada ao treinamento induz alterações funcionais e morfológicas no músculo esquelético. Entretanto, não estão bem definidos os efeitos da suplementação com creatina durante o treinamento resistido sobre o colágeno intersticial e a expressão de cadeias pesadas de miosina (MyHC) no músculo esquelético. Objetivo: Analisar a influência da suplementaçã com creatina sobre a expressão de MyHC e fração intersticial de colágeno em diferentes músculos esqueléticos de ratos submetidos a treinamento físico resistido. Material e Métodos: Ratos Wistar (n=24) foram distribuídos em quatro grupos: Controle (C), Creatina (Cr), Treinamento Resistido (TR) e Treinamento Resistido e Creatina (Tcr). Os grupos C e TR receberam dieta comercial padrão, enquanto Cr e Tcr receberam dieta com 2% de creatina. Os animais TR e Tcr realizaram protocolo de treinamento resistido em escada, 3x/semana, por 12 semanas. Posteriormente, foi realizada eutanásia dos animais e amostras de sóleo e gastrocnêmio foram usadas para análise histológica e expressão de MyHC por meio de eletroforese. Estatística: Two-Way ANOVA e Tukey. Significância de 5%. O protocolo experimental foi aprovado pela Comissão de Ética no Uso de Animais da Universidade Federal de Mato Grosso do Sul (CEUA/UFMS), protocolo n° 873/2017. Resultados: No gastrocnêmio, a porcentagem de MyHC IIx foi maior no TR do que em C (C: 6,25±2,69; Cr: 8,89±2,94; TR: 11,47±3,73; Tcr: 12,30±6,58 %). No sóleo, a taxa de MyHC IIa não diferiu entre os grupos. A fração intersticial de colágeno de ambos os músculos avaliados mostrou-se maior em resposta ao treinamento físico resistido, per se. Conclusão: A prática de treinamento físico resistido resultou em remodelação intersticial em diferentes tipos de músculo esquelético e maior expressão de isoformas de MyHC Iix no músculo gastrocnêmio em ratos expostos ou não à suplementação com creatina. Apoio: UFMS, CAPES (Cód.001), CNPq

Beneficial Effects of Physical Exercise on Functional Capacity and Skeletal Muscle Oxidative Stress in Rats with Aortic Stenosis-Induced Heart Failure

Objective. We evaluated the influence of exercise on functional capacity, cardiac remodeling, and skeletal muscle oxidative stress, MAPK, and NF-B pathway in rats with aortic stenosis-(AS-) induced heart failure (HF). Methods and Results. Eighteen weeks after AS induction, rats were assigned into sedentary control (C-Sed), exercised control (C-Ex), sedentary AS (AS-Sed), and exercised AS (AS-Ex) groups. Exercise was performed on treadmill for eight weeks. Statistical analyses were performed with Goodman and ANOVA or Mann-Whitney. HF features frequency and mortality did not differ between AS groups. Exercise improved functional capacity, assessed by maximal exercise test on treadmill, without changing echocardiographic parameters. Soleus cross-sectional areas did not differ between groups. Lipid hydroperoxide concentration was higher in AS-Sed than C-Sed and AS-Ex. Activity of antioxidant enzymes superoxide dismutase and glutathione peroxidase was changed in AS-Sed and restored in AS-Ex. NADPH oxidase activity and gene expression of its subunits did not differ between AS groups. Total ROS generation was lower in AS-Ex than C-Ex. Exercise modulated MAPK in AS-Ex and did not change NF-B pathway proteins. Conclusion. Exercise improves functional capacity in rats with AS-induced HF regardless of echocardiographic parameter changes. In soleus, exercise reduces oxidative stress, preserves antioxidant enzyme activity, and modulates MAPK expression

Beneficial Effects of Physical Exercise on Functional Capacity and Skeletal Muscle Oxidative Stress in Rats with Aortic Stenosis-Induced Heart Failure

Objective. We evaluated the influence of exercise on functional capacity, cardiac remodeling, and skeletal muscle oxidative stress, MAPK, and NF-κB pathway in rats with aortic stenosis- (AS-) induced heart failure (HF). Methods and Results. Eighteen weeks after AS induction, rats were assigned into sedentary control (C-Sed), exercised control (C-Ex), sedentary AS (AS-Sed), and exercised AS (AS-Ex) groups. Exercise was performed on treadmill for eight weeks. Statistical analyses were performed with Goodman and ANOVA or Mann-Whitney. HF features frequency and mortality did not differ between AS groups. Exercise improved functional capacity, assessed by maximal exercise test on treadmill, without changing echocardiographic parameters. Soleus cross-sectional areas did not differ between groups. Lipid hydroperoxide concentration was higher in AS-Sed than C-Sed and AS-Ex. Activity of antioxidant enzymes superoxide dismutase and glutathione peroxidase was changed in AS-Sed and restored in AS-Ex. NADPH oxidase activity and gene expression of its subunits did not differ between AS groups. Total ROS generation was lower in AS-Ex than C-Ex. Exercise modulated MAPK in AS-Ex and did not change NF-κB pathway proteins. Conclusion. Exercise improves functional capacity in rats with AS-induced HF regardless of echocardiographic parameter changes. In soleus, exercise reduces oxidative stress, preserves antioxidant enzyme activity, and modulates MAPK expression

Patologia do Coração na AIDS. Estudo de 73 Necropsias Consecutivas

Purpose - To study the incidence and the etiology of the cardiac lesions in AIDS patients. Methods - The autopsy protocols and the filled slides of the heart from 73 consecutive AIDS patients were reviewed. There were, at least, 2 slides of each heart stained by haematoxylin-eosin; when indicated, Ziehl-Nielsen, Gram and Gomori Grocott stains were used. Results - No cause of death was assigned to the heart. There was involvement of the heart in 66 (90%) cases. Marked atrophy of cardiac fibers with or without lipomatosis was observed in 38 patients. Interstitial infiltrates of myocardium were present in 38 necropsies and in 13 of these cases a probable pathogen was demonstrated: cryptococcus neoforms in three cases and mycobacteria tuberculosis, atypical mycobacteria, toxoplasma gondii, trypanosoma cruzi and cytomegalovirus in two cases each. Bacterial endocarditis was found in 4 autopsies and Kaposi sarcome in one. The pericardium was involved in 22 cases; in 12 there was only non specific mononuclear infiltration. Conclusion - Autopsy examination of the heart from AIDS patients revealed frequent pathologic involvement