Amine oxidase histochemistry of the human uterus during the menstrual cycle

Summary The enzymes monoamine oxidase A (MAO A), monoamine oxidase B (MAO B) and benzylamine oxidase (BzAO) have been localized histochemically in the human uterus during various phases of the menstrual cycle. The results show a large increase in MAO A activity in the endometrial gland cells in the secretory phase of the cycle. MAO B activity was found in both endometrium and myometrium but did not show a cyclical variation in activity. BzAO was localized primarily in the tunica media of the myometrial blood vessels. These observations have been supported by parallel biochemical assays.This research was supported by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CN Pq), Brazil and The Wellcome Trust, U.K., who defrayed the salary of Rachel Lewinsohn