A sensitive radioreceptor assay for follicle stimulating hormone with PMS-primed immature rat ovary.

After a single PMS (50 IU) injection to 25-day-old rats, FSH receptor content of the ovarian tissue increased progressively for 4 days, then showed a tendency to decrease, while LH receptor content remained unchanged for 3 days, then gradually increased. From these facts, we established a radioreceptor assay system, employing 3,000 rpm precipitates of homogenates of the ovaries obtained 3 days after PMS injection as the receptor preparation. The dissociahe standard curve was obtained with 0.