Presence of gap junctions in the myometrium of women during various stages of menstruation.

Myometrial tissues from 36 women who underwent hysterectomy at various stages of the menstrual cycle were examined in the electron microscope for the presence of gap junctions. Gap junctions were present between smooth muscle cells in some of the tissues from women with dysmenorrhea, during menstruation and at other times. The suggestion is made that gap junctions may form between myometrial cells in nonpregnant women in response to physiologic or pathologic stimuli, such as the production of prostaglandins, and the presence of the contacts may result in contractions of the uterus.