[Effect of oxytocin on the calcium pump in myometrium sarcolemma]

Oxytocin (10(-7) M) administered inside the myometrium sarcolemma vesicles closed outward by the cytoplasmic side is shown to inhibit Mg2+, ATP-dependent Ca2+ accumulation in these structures having no effect on the passive release of cation out of them. According to these results and to the data available in literature on the inhibitory action of the peptide hormone on Mg2+, Ca2+-ATPase of myometrium sarcolemma a conclusion is drawn that oxytocin inhibits the Ca pump activity in plasma membranes of the myometrium cells.