Subject(s)
Aging/physiology , Heart Ventricles/ultrastructure , Animals , Coturnix , Female , Heart Ventricles/growth & development , MaleABSTRACT
In the present review the structural role of noncoding DNA, mechanisms of differential staining of mitotic chromosomes, and structural organization of different levels of DNA compactization are discussed. A structural-functional model of the mitotic chromosome is proposed based on the principle of discreteness of structural levels of DNA compactization.
Subject(s)
Chromosomes, Human/chemistry , Chromosomes, Human/metabolism , Chromosomes/chemistry , Chromosomes/metabolism , Mitosis , Animals , Calcium/metabolism , Chromatin/chemistry , Chromatin/ultrastructure , Chromosomal Proteins, Non-Histone/chemistry , Chromosomal Proteins, Non-Histone/metabolism , Chromosomes/ultrastructure , Chromosomes, Human/ultrastructure , DNA/chemistry , Euchromatin/chemistry , Euchromatin/metabolism , Heterochromatin/chemistry , Heterochromatin/metabolism , Histones/chemistry , Histones/metabolism , Humans , InterphaseABSTRACT
The mitochondriom of left-ventricular cardiomyocytes in rats subjected to head-down tilt was studied at the electron microscopic level. The ultrastructure of individual mitochondria was disturbed and the number of intermitochondrial contacts in the perinuclear zone increased after 30-day head-down tilt. These parameters did not return to normal over 30 days after 30-day tilt. Repeated 14-day head-down tilt led to a more pronounced increase in the number of intermitochondrial contacts, mitochondria with abnormal ultrastructure were still observed.
Subject(s)
Head-Down Tilt/adverse effects , Mitochondria/ultrastructure , Myocytes, Cardiac/ultrastructure , Animals , Heart Ventricles/ultrastructure , Male , Microscopy, Electron , Rats , Rats, Wistar , Time Factors , Weightlessness SimulationSubject(s)
Hindlimb Suspension/physiology , Myocytes, Cardiac/ultrastructure , Animals , Cell Size/physiology , Heart Ventricles/cytology , Male , Microscopy, Electron , Mitochondria/ultrastructure , Myocytes, Cardiac/cytology , Myofibrils/ultrastructure , Rats , Rats, Wistar , Time Factors , Weightlessness SimulationABSTRACT
2G-hypergravity during 33-days led to hypertrophy of cardiomyocytes (CMC) in rat left ventricle accompanied by capillary number and diameter growth. CMC ultrastructure was normal at all experimental stages. Number of intermitochondrial junctions (IMJ) rose after 33 days of 2G in subsarcolemmal pericapillary zone of CMC, indicating probably to enlarged CMC energy needs. Changes in myocardium achieved during 33 days of 2G were reversible at 39 days of 1G (except IMJ number). Repeated 5-days 2G influence (after 33 days of primary 2G influence followed by 39 days of 1G) led again to CMC hypertrophy and to IMJ number rise in all zones of mitochondria localisation. Primary 5-days 2G influence didn't result in CMC hypertrophy, IMJ number rose only in subsarcolemmal pericapillary zone.
ABSTRACT
For elucidation of secretory cardiomyocytes adaptation to prolonged and repeated influence of changed gravity the ultrastructural and morphometrical analysis of right atrium cells was made in rats after they were exposed to primary and repeated 2G-centrifugation in ground-based experiment. It was found prolonged 2G-hypergravity resulted in hypertrophy of right atrium cardiomyocytes and stimulated of their mitochondrial associative activity and granular secretion; repeated influence induced changes differed from those after single influence.
