Plasma Monoamine Oxidase Activity in Regularly Menstruating Women and in Amenorrheic Women Receiving Cyclic Treatment with Estrogens and a Progestin

Abstract
Plasma monoamine oxidase (MAO) activity is examined in the pre- and post-ovulatory phases of the menstrual cycle of regularly menstruating women, in amenorrheic women, in postmenopausal women, and in amenorrheic and post-menopausal women treated with estrogens and a progestin. MAO activity was significantly greater in the post-ovulatory than the pre-ovulatory phase of the cycle. The MAO activity of untreated amenorrheic and post-menopausal women was significantly greater than the postovulatory phase of regularly menstruating women. Estrogen treatment significantly reduced MAO activity in the amenorrheic and post-menopausal women; estrogen plus progestin significantly increased the MAO activity of the amenorrheic women over their estrogen treatment levels. The significance of the ovarian hormones for adrenergic brain processes is discussed.