Gap junctions in the myometrium of hypophysectomized estrogen-treated rats

Gap junctions, which appear in the myometrium at parturition, are believed to permit the flow of ions between smooth muscle-cell interiors thereby facilitating coordinated contractions. Gap junctions are not observed in thin-sectioned myometrium of immature hypophysectomized rats. Following estrogen administration, numerous gap junctions are present suggesting that this hormone is capable of promoting electrotonic coupling in uterine smooth muscle.