RESUMEN
The age-related features of ultrastructural reorganization of cardiomyocytes were studied in rats with anthracycline-induced injury. The development of regenerative and plastic insufficiency of cardiomyocytes in animals of various age groups was accompanied by stereotypic ultrastructural reorganization. The major changes concerned the nucleus, myofibrillar compartment, and rough sarcoplasmic reticulum. Intracellular reorganization of cardiomyocytes in young animals was observed in the same period, but included a greater decrease in the volume density of myofibrils as compared to that in old rats. The recovery of cardiomyocyte ultrastructure in young animals occurred in the earlier period. Cardiomyocytes of old rats were characterized by greater structural modification of mitochondria and considerable area of lytic changes in myofibrillar bundles. Cardiotoxicity of doxorubicin in young animals was manifested in severe destruction of the capillary endothelium, which occurred in the early period after treatment.
Asunto(s)
Cardiomiopatías/patología , Miocardio/ultraestructura , Miocitos Cardíacos/ultraestructura , Factores de Edad , Animales , Cardiomiopatías/inducido químicamente , Núcleo Celular/patología , Núcleo Celular/ultraestructura , Doxorrubicina/toxicidad , Endotelio Vascular/patología , Endotelio Vascular/ultraestructura , Inyecciones Intraperitoneales , Masculino , Microscopía Electrónica , Mitocondrias Cardíacas/patología , Mitocondrias Cardíacas/ultraestructura , Miocardio/patología , Miocitos Cardíacos/efectos de los fármacos , Miocitos Cardíacos/patología , Miofibrillas/patología , Miofibrillas/ultraestructura , Ratas , Ratas Wistar , Retículo Sarcoplasmático/patología , Retículo Sarcoplasmático/ultraestructuraRESUMEN
Structural reorganization of the myocardium was studied in rats of various age groups (periods of progressive and regressive growth) with anthracycline-induced regenerative and plastic insufficiency. The specific features included the prevalence of cardiomyocyte lysis, diffuse and microfocal changes, and diffuse or microfocal cardiosclerosis. During the late ontogeny, myocardial damage was characterized by more pronounced cardiosclerosis (primarily microfocal cardiosclerosis). The development of regenerative and plastic insufficiency of cardiomyocytes determines dilatation remodeling of the heart in rats of various age groups. Comparative study of the morphogenesis of heart failure in rats of various age groups showed that cardiotoxic exposure during the early ontogeny induced more pronounced remodeling of the heart compared to that in late ontogeny. Differences in proliferative activity of cardiomyocytes and ability for hypertrophic growth are the main cellular mechanisms of age-related features of structural reorganization.
