Measurement of human epidermal growth factor receptor in the endometrium during the menstrual cycle

To evaluate a potential physiologic role of the epidermal growth factor receptor in the endometrium, we measured the receptor content at different times in the menstrual cycle. Endometrial biopsy specimens were obtained from 28 normal women during the proliferative or secretory phase of the menstrual cycle, and the epidermal growth factor receptor content was determined. When the number of epidermal growth factor binding sites were evaluated as a function of time within each phase, a difference between phases became evident. The level of receptor increased during the proliferative phase with a maximum just before ovulation (p = 0.0128, r = 0.748). The epidermal growth factor receptor level decreased during the secretory phase, reaching a minimum before menses (p = 0.0001, r = 0.843). We conclude that the endometrial epidermal growth factor receptor content is cycle dependent, being maximal during the periovulatory period and minimal just before or during menses. These findings further suggest a physiologic role for epidermal growth factor in the proliferation and differentiation of the endometrium.