Age related changes in gastrocnemius, diaphragm and heart muscles with special reference to SDH and m-ATPase

Age related histochemical and biochemical decrease in succinic dehydrogenase (SDH) and myofibrillar ATPase (m-ATPase) activity was observed in diaphragm, leg and heart muscles of rat. The effects of ageing varied in intensity in different muscle types and were more pronounced in fast muscles. Decrease in m-ATPase may be the result of age related decrease in number of contractile elements revealed by low content of electrophoretically analysed myofibrillar proteins. Restructuring in nerve muscle junction reported, was in relation to normal variation in functional demands of rat from different age groups because of transient changes in work load.