[Effect of periodic gravitation overloads on the physico-chemical properties and Ca2+ reactivity of actomyosin of the myocardium and skeletal muscles of albino rats].

Under the influence of regular acceleration (5 g for 25 min during 15 days) Mg2+-ATPase activity of native and desensitized actomyosin of the myocardium and femurs of white rats increased. This was in correlation with increases in the rate of actomyosin superprecipitation (Vspp) and in the surface charge of macromolecules. The control animals showed a decrease in the inhibition of Mg2+-ATPase and Vspp of native actomyosin by tropomyosin-troponin. Ca2+ in a concentration of 10(-7) - 10(-4) M stimulated Mg2+-ATPase of native actomyosin of experimental animals by 50% only, but the maximum activation of Vspp was significantly higher than in the controls. It is assumed that these changes tend to increase the efficiency of the actomyosin system.