ANALYSIS OF QUALITATIVE AND QUANTITATIVE MORPHOLOGICAL CHANGES AND Ca~(2+) REGULATION OF ORGANELLES IN AGING MYOCARDIUM / 解剖学报

ABSTRACT

Objective To study the mechanism of myocardical aging. Methods Wistar rats used were divided aging group (22 months old) and adult group (7 months old). Qualitative morphological changes of organelles of myocardium were observed by TEM. Quantitative morphological changes of organelles of myocardium were determined by stereological method, Ca 2+ regulation of organelles of myocardium were analysed by EDS. Results Compared with adult group, aging group:(1) The nuclei were indented, myofibril were arranged irregularly, intercalated disk were separated, mitochondria and sarcoplasmic reticulum were swelled, lipofuscin and residual body were increased. (2) The volume of myocardium not occupied by myocyte were increased, the volume density of mitochondria and sarcoplasmic reticulum were reduced, specific surface of outer membrance of mitochondria inter membrane plus cristae of mitochondria and the membrane of sarcoplasmic reticulum were also reduced. (3) Ca 2+ in myofibril and mitochondria were increased, but Ca 2+ in sarcoplasmic reticulum were decreased. Conclusion The contractility of aging myocardium were declined, the morphological changes and Ca 2+ regulation of mitochondria and sarcoplasmic reticulum might be directly related to myocardical aging.