[Uterine contractions in non-pregnant women. How are they handled? what is their significance?].

Although myometrial activity in the non-pregnant woman is essential for the expulsion of shed endometrium and blood during menstruation, as well as for the transport of sperms or a newly fertilised ovum, myometrial hyperactivity is associated with primary or secondary dysmenorrhoca. Recordings of intrauterine pressure in non-pregnant women have shown the pattern and propagation of uterine contractions to vary with the phases of the menstrual cycle. The myometrial hyperactivity during dysmenorrhoea and its effect on uterine blood flow have also been clarified. The cyclical variation in myometrial activity is largely the result of the genomic and non-genomic effects of ovarian steroids. Increased secretion of vasopressin and prostaglandin F2 alpha may be an importantaetiological factor involved in the myometrial hyperactivity associated with primary dysmenorrhoea. The effect of vasopressin in the uterus is mediated via the V1 receptor involved in the mediation of its effect in the kidney. Myometrial hyperactivity in non-pregnant women can be regulated by a combination of an oral contraceptive, a prostaglandin synthesis inhibitor and a V1 receptor antagonist.