(Mainly at threat of premature births) apply various medicines of neurotropic and myotropic action to reduction of sokratitelny uterine activity (sedatives, cholinolytics, spasmolysants, etc.). In recent years for this purpose began to appoint also A b - adrenostimulyator. For this purpose data on a role of adrenoceptors in regulation of sokratitelny activity of a uterus and about a possibility of regulation of this activity by the substances stimulating or blocking Aa - and A b - adrenoceptors formed the basis.
It is established that Aa aktivition - adrenoceptors and blockade of Ab - adrenoceptors lead to strengthening, and blockade of A an - adrenoceptors or stimulation of A b - adrenoceptors - to slowing down of sokratitelny function of a uterus.
Different A b - adrenomimetik have the braking impact on myometrium (Isadrinum, ortsiprenalin, Fenoterolum, salbutamol, terbutalin, etc.).
Experience of studying A b - adrenomimetik shows that they improve also uteroplacental blood circulation (not only due to myometrium relaxation, but also thanks to expansion of arterioles and increase in a blood-groove).
Implementation of Ab - adrenostimulyator as tokolitichesky means for prevention and therapy of the menacing termination of pregnancy was a large contribution to obstetric and gynecologic practice.