[Influence of heavy metal ions on the ATPase activity of actomyosin complex and myosin subfragment-1 from smooth muscle of the uterus].

The effect of divalent cations--Co2+, Cu2+, Mn2+ and Ni2+ (5 mM) on the activity of actomyosin complex ATPase and ATPase of subfragment-1 (S1,head) of myosin from smooth muscle of the uterus was studied. It has been shown that Co2+, Mn2+ and Ni2+ inhibited, while Cu2+ activates the enzyme activity of both actomyosin and myosin S1. Mg and Mn ions had practically no effect on the emission intensity of eosin Y associated with actomyosin, while one could observe the most marked suppression of emission of related fluorescent probe in the presence of Cu cations and less pronounced suppression in the presence of Co2+.

[Effect of dielectric permeability and temperature of culture media on inhibitory action of eosin Y on actomyosine ATPase of the uterine smooth muscles].

Influence of dielectric permeability and incubation medium temperature on sensitivity of ATPase of contractile protein complex to eosin Y was studied on preparations of uterine smooth muscle actomyosin. It was shown, that a decrease of dielectric permeability from 74.1 to 68.