Relationship between body composition and physical activity and the development of experimental cardiac necrosis in male rats of different age

Abstract

Changes of morphological characteristics and the functional capacity during ageing are associated with various other degenerative changes. Involution of internal organs (brain, liver, spleen, stomach, etc.) takes place mainly as a result of the reduced density of the capillary network. The permeability of capillaries declines, and so does the body water content; more calcium, lipofuscin and other substances are deposited in tissues along with the reduction of LBM. The general adaptability of the organism to the action of various factors is reduced (Shock 1972) and the aged organism is also more sensitive to various noxious agents. These changes have a considerable individual variability and their course, rate and time at which they commence and develop during ontogenesis depend on many circumstances such as e.g. genetic factors, the past and present health and nutritional status etc. The role of many factors which influence the course of ageing has not so far been elucidated; lack of physical activity is considered as one of the important supporting factors in the onset of senile changes from the functional and morphological aspect (Shock 1972) and also in the development of atherothrombosis (Wright 1972) and other pathological processes (Arinchin 1972, Sirotinin 1972, Chebotarev 1972).