[Effect of vincamine, vinervine and serotonin on the sexual cycle in rats].

With a prolonged enteral introduction indole alkaloids vincamine (5--20 mg/kg), vinervine (5 mg/kg) and serotonin (2 mg/kg) significantly lengthen the duration of the sex cycle through extending the estrus cycle (vincamine, vinervine and serotonin) and diestrus (serotonin). Without changing the weight of the uterus the studied alkaloids tend to significantly increase the weight of the ovaries and the number of follicles therein. In test with sexually mature castrated and also sexually immature (both alkaloids) and hypophysectomized (vincamine) animals these alkaloids fail to display any estrogenic action.