[Possible mechanism of the regulation of smooth muscle relaxation by calcium ions].

Kinetics of Ca2+ energy-dependent transport in sarcolemma and mitochondrion fractions of myometrium was studied. On the basis of the results obtained the mechanism of calcium control of smooth muscle relaxation was analysed. In terms of this mechanism kinetic curves of myometrium relaxation were calculated. It follows from their pattern that the mitochondria play the role of the main intercellular depo of Ca2+, while the calcium pump of the sarcolemma carries out fine regulation of this process making its contribution to relaxation at its later stage.