Epidermal growth factor-like immunoreactivity in human endometrium.

Epidermal growth factor (EGF)-like immunoreactivity was detected in human endometrial tissues. The concentrations of the immunoreactivity fluctuated during the menstrual cycle. The highest levels were observed in the late proliferative phase with the concentrations being 0.50 +/- 0.06 ng/mg protein (M +/- SE, n = 5). Considering the presence of EGF receptors in human endometrium, EGF-like peptides may act in autocrine or paracrine fashions in human endometrium.