Specific binding of human chorionic gonadotropin to human corpora lutea in the menstrual cycle

Luteal tissue from 26 premenopausal women undergoing surgery for nonendocrine disease was examined for specific binding to human chorionic gonadotropin. Results showed a nadir in the percentage of binding on day 10, with a gradual increase until maximal binding was obtained on days 22 through 26. Binding then markedly declined to that seen on day 1 of the menses and decreased gradually to its lowest level on day 10.