[Oxidative enzyme activity of the tricarboxylic acid cycle in rat skeletal muscles in hypokinesia].

The study of 165 rats exposed to 60-day hypokinesia demonstrated a decrease in the quantity of mitochondrial protein and a decline in the activity of mitochondrial forms of NADP-isocitrate dehydrogenase (NADP-ICDH) and NAD-malate dehydrogenase (NAD-MDH), as well as NAD-ICDH, succinate dehydrogenase (SDH) and alpha-ketoglutarate dehydrogenase (alpha-KGDH). The maximum decline in the protein content was seen on day 60, and in the enzyme activity on day 7. As the hypokinetic exposure continued, the activity of mitochondrial NAD-MDH and NADP-ICDH slightly increased. The NADP-MDH activity decreased only at later stages of hypokinesia. The changes in cytoplasmic NAD-MDH, NADP-ICDH and NADP-MDH were less expressed. On day 25 of the recovery period the activity of NAD-ICDH and NADP-ICDH was significantly higher than in the controls, that of mitochondrial NAD-MDH returned to the normal, and the activity of SDH and alpha-KGDH remained noticeably lowered.