Electrical activity in the human oviduct after the menopause.

Electrical activity was recorded in 18 morphologically normal human oviducts excised from 17 women during hysterectomy. All women were in the first five years after menopause. The first part of the oviduct to become inactive after menopause was the isthmus near the uterus or the ampullary-isthmic junction. The region which exhibited electrical activity last was the ovarian end of the tube. The typical wave-form of electrical activity in post-menopausal oviducts resembled that recorded during the follicular phase in fertile women: a single smooth wave lasting 3-5s. In three cases, over a bulbous swelling of the ampulla, this typical activity was replaced in continuous, high frequency activity. A hypothesis is provided that the observed changes in electrical activity may be related to certain clinical phenomena such as the increased incidence of tubal pregnancy in the pre-menopause.