[Effects of hypokinesia of different duration on electrolyte contents in muscle tissue of rats]. / Vliianie gipokinezii razlichnoi prodolzhitel'nosti na soderzhanie élektrolitov v myshechnoi tkani krys.

The study has demonstrated a significant increase in blood levels of potassium on Day 3 of hypokinesia. Sodium content and the sum of two ions were decreased on Day 3 and increased on Day 10 of the exposure. Significant changes in the calf muscles (musculus gastrocnemius), i.e. decreased potassium and increased sodium concentrations, were observed on Days 10, 30, 45, 70, 90, and 140. The total content of potassium and sodium ions remained reduced. Analysis of parameters characterising the ion gradients points to lowered activity of Na-K-dependent ATP-ase, fewer number of ion-binding groups of tissue anions. In myocardium, these shifts were less pronounced and included an insignificant loss of potassium ions and gain in sodium ions the gradient of which was most significant on Days 10, 30, and 45. The general trend of changes in the ion balance implies some unified mechanisms of the hypokinesia effects on the muscular tissue, associated with the disorders in energy metabolism, change in hormonal status, and activation of catabolic processes in immobilised body giving rise to deconditioning and asthenization.

[Effect of immobilized adrenaline on the state of the adenylate cyclase system in the cardiac and skeletal muscles of rats in the recuperative period after physical exertion]. / Deistvie immobilizovannogo adrenalina na sostoianie adenilattsiklaznoi sistemy v serdechnoi i skeletnykh myshtsakh krys v vosstanovitel'nyi period posle fizicheskoi nagruzki.

It is shown that in the rehabilitation period after a single long physical load the adenylate cyclase activity and cAMP content in the skeletal muscle are low and normalize by the 48th and 36th h, respectively. These indices in the myocardium in the nearest rehabilitation period increase considerably, gradually normalizing by 24th and 48th h, respectively. Immobilized epinephrine accelerates normalization of the adenylate cyclase activity and cAMP content in the skeletal muscle and in myocardium in the rehabilitation period after physical load, the phosphodiesterase activity being unchanged.