Studies of the spontaneous motility and the effect of histamine on isolated myometrial strips of the nonpregnant human uterus: the influence of various uterine abnormalities.

We investigated the spontaneous uterine activity of isolated corpus uteri myometrial strips from 30 patients with nonpathologic myometrium, 26 patients with uterine myoma, 23 patients with uterine adenomyosis, and three patients with uterine malignancy. We also investigated the influence of these conditions on the response of the uterus to histamine. The results show the same qualitative cyclic changes of the spontaneous motility of isolated myometrial strips throughout the menstrual cycle in all the abnormalities studied. These changes are characterized by a low amplitude and high frequency of spontaneous contractions in the proliferative phase and lower frequency with higher amplitude of contractions in the secretory phase. The isolated strips from patients with myomas present the highest spontaneous activity in reproductive age and preclimacteric women, but not in menopausal women. Histamine produced concentration-related contractions that are not significantly different in all the myometrial strips studied.