RESUMO
PURPOSE: In the present study we evaluated the morphology of left ventricular cardiomyocytes of albino rats during pregnancy and puerperium by means of transmission electron microscopy. METHODS: Once pregnancy was confirmed, 77 rats were randomly divided in two groups, respectively, gestation (G) and puerperium (P). The animals of the gestation group were divided into four subgroups, according to gestational age: 1st (G-A), 7th (G-B), 14th (G-C) and 21st (G-D) days of pregnancy. The group defined as puerperium was divided into three subgroups: 7th (P-A), 14th (P-B) and 21st (P-C) days of puerperium. In the end of each established period, the animals were sacrificed and fragments of the medium third of the left ventricle were resected and routinely prepared for electron microscopy analysis. RESULTS: The results obtained with transmission electron microscopy analysis revealed a gradative increase of the cardiomyocytes during pregnancy (increase of myofibrils, which are permeated by numerous mitochondria at the end of gestation). The blood capillary wall showed progressive thinning, with an increase of pynocytotic vesicles in endothelial cells, and intense sarcolemal folding at T-tubule level (capillary tunnels). In the puerperium group, there is a progressive regression in these alterations returning to pre-gestational level at the end of the puerperium cycle. These findings indicate the occurrence of hypertrophy of cardiomyocytes during pregnancy. CONCLUSION: The findings indicate the occurrence of hypertrophy of cardiomyocytes during pregnancy.
Assuntos
Ventrículos do Coração/ultraestrutura , Fibras Musculares Esqueléticas/ultraestrutura , Período Pós-Parto , Adaptação Psicológica/fisiologia , Animais , Eletromiografia , Feminino , Ventrículos do Coração/citologia , Hipertrofia Ventricular Esquerda/fisiopatologia , Microscopia Eletrônica , Gravidez , Ratos , Ratos WistarRESUMO
PURPOSE: In the present study we evaluated, by light microscopy, and throughout morphometry, whether hypertrophy of cardiac striated muscular fibers of left ventricular occur in albino rat, during pregnancy. METHODS: After maiting, 12 nuliparous rats were divided into four groups with three animals for each group. The female rats corresponding to each group were killed at 1st, 7th, 14th and 21st days of pregnancy. RESULTS: Observation, on light microscopy (H.E) had at one view, did not display any alterations during pregnancy. However, the morphometry revealed that nuclei of cardiomyocytes are augmented in volume at 14th day of pregnancy and statistically significant data show the hypertrophy. CONCLUSION: The obtained data show the existence of a dinamic and reversible process of ventricular remodelling in consequence of adaptation physiological alterations of the cardiovascular normal pregnancy.
Assuntos
Ventrículos do Coração/citologia , Animais , Feminino , Hipertrofia Ventricular Esquerda/fisiopatologia , Gravidez , RatosRESUMO
Objetivo. No presente estudo avalianos, por intermédio da microscopia eletrônica de transmissão, a morfologia dos cardiomiócitos do ventrículo esquerdo de ratas albinas no decorrer do ciclo gravídico-puerperal. Métodos. Obtida a prenhez, 77 ratas foram divididas ao acaso em dois grupos denominados, respectivamente, de: gestação (G) e puerpério (P). Os animais pertencentes ao grupo gestação foram ainda subdivididos em quatro subgrupos, de acordo com a idade gestacional; 1§ (G-A), 7§ (G-B), 14§ (G-C) e 21§ (G-D) dias de prenhez. O grupo definido como puerpério foi também subdividido em três subgrupos; 7§ (P-A), 14§ (P-B) e 21§ (P-C) dias de puerpério. Findo o período estabelecido para cada subgrupo, os animais foram sacrificados, sendo coletados fragmentos do terço médio do ventrículo esquerdo, os quais após processamento apropriado, permitiram observação adequada à microscopia eletrônica de transmissão. Resultados. Os resultados hipertrofia gradativos dos cardiomiócitos no decorrer da prenhez (aumento das miofibrilas, que ao final da gestação apresentaram-se entremeadas de numerosas mitocôndrias). As paredes dos capilares sangüíneos, progressivamente, tornaram-se mais delgadas, com aumento das vesículas de pinocitose no interior das células endoteliais. Revelou ainda, acentuadas dobras do sarcolema em nível dos túbulos T (túneis capilares). No grupo puerpério, notamos gradativa regressão nessas alterações, com retorno às características pré-gestacionais. Os achados demonstram a ocorrência de hipertrofia no decorrer da gestação. Conclusão. Durante a prenhez há hipertrofia em cardiomiócito do ventrículo esquerdo com regressão durante o puerpério.
Assuntos
Feminino , Gravidez , Animais , Ratos , Prenhez , Fibras Musculares Esqueléticas/ultraestrutura , Ventrículos do Coração/ultraestrutura , Adaptação Psicológica/fisiologia , Microscopia Eletrônica , Ratos Wistar , Hipertrofia Ventricular Esquerda/fisiopatologia , Eletromiografia , Ventrículos do Coração/citologiaRESUMO
Authors present the case of a 37-year-old man admitted to the emergency room of Universidade Federal de São Paulo-Escola Paulista de Medicina, with hyperosmolar coma, following progressive muscle discomfort and loss of renal function, with further need of dialysis therapy. Initial laboratory evaluation showed marked hyperglycemia, hypernatremia, hyperosmolarity, and high levels of creatinine. In the evolution he presented an elevation of creatino-phosphokinase levels in parallel with increasing levels of urea and creatinine. Urinalyses showed progressive increase in proteinuria and hematuria. A muscle biopsy was performed and confirmed the presence of muscular necrosis. The purpose of this paper is to emphasize hyperosmolarity as a newly described cause of rhabdomyolysis. The authors point out its multifactorial physiopathology and also stress the relatively common occurrence of acute renal failure (ARF) following an episode of rhabdomyolysis, and the poor prognosis that this complication represents.