RESUMEN
There were studied the cardiomyocyte ultrastructure, contractile function, actomyosin complex composition and property of the rat ventricular myocardium after repeated gravitational overloading and following rest. In the hypergravitation period cardiomyocyte changes carry destructive character or are regenerative processes manifestation. They are comparable with myocardial contractile function state and with displacements in molecular structure of myofibrillar apparatus. At rest conditions the liquidation of cardiomyocytes destructive changes falls behind the normalization of contractile and regulatory cells of physico-chemical characteristics. The possible reasons of this phenomenon are discussed.
Asunto(s)
Actomiosina/análisis , Gravitación , Contracción Miocárdica , Miocardio/ultraestructura , Animales , Electroforesis , Femenino , Masculino , Miocardio/citología , Miocardio/patología , Ratas , Regeneración , DescansoRESUMEN
In adult rats with experimental myocardial infarction and after swimming training load in atrial and ventricular cardiomyocytes a number of nuclei changes are revealed, which are characterized by deep strangulation with rounded borders, by fissural invagination of nuclear surface in transversal or longitudinal directions, by the presence of long intersection and micronucleus between the nuclei, by close nuclei location. The transferred pictures may be interpreted as manifestation of direct division of interphase nuclei in the absence of figures of mitotic division.
Asunto(s)
Núcleo Celular/ultraestructura , Miocardio/ultraestructura , Envejecimiento , Animales , División Celular , Microscopía Electrónica , Infarto del Miocardio/patología , Miocardio/patología , RatasRESUMEN
Ultrastructural studies of cardiomyocytes during experimental aorta coarctation enabled one to divide them into 6 types: with mitochondrial swelling and enlargement of the sarcoplasmic reticulum; with primary damage to myofibrils; with disintegration of ultrastructure because of edema; with hypertrophy and hyperplasia of ultrastructures; without essential changes in organelles; and with concomitant changes in mitochondria and myofibrils. Such different reactions of cardiomyocytes are regarded as an adaptation mechanism that ensures the maintenance of heart function under extreme conditions.