Response of mouse graafian follicles in organ culture to varying doses of follicle-stimulating hormone and luteinizing hormone.

The response of mouse ovaries maintained in organ culture to follicle-stimulating hormone (FSH), LUTEINIZING HORMONE (LH) and human chorionic gonadotrophin (HCG) was assessed using quantitative histological and radioimmunoassay techniques. In terms of the induction of preovulatory maturation in follicular oocytes, 1 mugFSH/ml medium was as effective as 10 mugLH/ml. The lowest doses of HCG and LH used (0.2 i.u./ml and 1 mug/ml respectively) had no effect on oocyte maturation, whereas the response to FSH WAS VIRTUALLY UNCHANGED IRRESPECTIVE OF DOSE (1-10 MUG/ML). When the level of progesterone in the medium at the end of organ culture was used as an index of ovarian response, LH was more effective than FSH and HCG, although all the hormones induced a significant increase, irrespective of dose. These results are discussed in terms of the mode of action of gonadotrophins in the processes culminating in ovulation.