Cyclic changes in epidermal growth factor receptor in human endometrium during menstrual cycle.

Epidermal growth factor (EGF), a potent mitogenic peptide, is known to be present in the fluid of the uterine cavity. Recent studies have demonstrated the messenger RNA for EGF in the rat uterus. Therefore, in an attempt to clarify its physiological role, we investigated the receptors for EGF in human endometrial tissues. The particulate fractions from endometrium possessed the capacity to bind EGF in a specific, saturable and reversible manner. The Scatchard plot was linear, showing a single class of the receptor with an apparent Kd of 3.8 X 10(-9) M. The amount of specific EGF binding was very low during menstruation and increased gradually, reaching its peak in the late follicular phase. There was an abrupt decline in the binding after ovulation with no change in the Kd value. These results imply the possible involvement of EGF in the process of proliferation of human endometrial tissues.