TISSUE RESPIRATION AND GLYCOLYSIS IN QUADRICEPS FEMORIS AND HEART OF RATS OF DIFFERENT AGES DURING HYPODYNAMIA

Tissue respiration and glycolysis are examined in m. quadriceps fermoris and heart of albino rats kept under ordinary conditions of life (control group) and under conditions of restraint hypodynamia (experimental group), aged 1 1 2-2 1 2, 6-8 and 24-25 months. The results are collated by groups in relation to age and to the experimental procedure. The study shows decreased oxygen consumption in m. quadriceps femoris and heart of old animals and high muscle values for endogenic lactic acid and for that derived from glycolysis. Under conditions of hypodynamia we observe in the muscle disappearance of age differences and approximation of the values to the level of those of old control animals. The high values of endogenic and glycolytic lactic acid in the muscles of young and old animals under conditions of hypodynamia are particularly notable. High activity of the glycolytic chain is observed in all age groups, both under conditions of hypodynamia and in old control animals. Similar tendencies are likewise observed the heart muscle. Conditions of restraint hypodynamia produce, in young rats, characteristics that often resemble those in old rats living in under ordinary conditions of life. © 1969.