ANTRAL FOLLICLE DEVELOPMENT AND IN-VITRO MATURATION OF OOCYTES FROM MACAQUES STIMULATED WITH A SINGLE SUBCUTANEOUS INJECTION OF PREGNANT MARES SERUM GONADOTROPIN

A single s.c. injection of 1000 IU of pregnant mare's serum gonadotrop hin (PMSG) stimulates the growth of multiple antral follicles in cynom olgus monkeys (Macaca fascicularis). The number of cumulus enclosed oo cytes (CEO) from six nonstimulated controls was 36 (mean = 6). In cont rast, a total of 95 CEO (mean = 31.7) were recovered from three animal s stimulated and ovariectomized 3 days later, while 385 CEO (mean = 12 8.3) were obtained from three animals stimulated and ovariectomized 4 days later. A comparison of the effects of highly purified human folli cle-stimulating hormone (FSH), human luteinizing hormone (LH) and huma n thyroid-stimulating hormone (TSH) on cultures of rhesus monkey (Maca ca mulatta) CEO cultured in medium 199 for 48 h showed that FSH and LH stimulated cumulus expansion but had moderate effects on the progress ion of meiosis. The progression that did occur seldom proceeded beyond the metaphase I stage. Human TSH had no demonstrable effect on cumulu s expansion and meiotic progression. In other experiments FSH, LH and oestradiol-17 beta were added jointly to medium CMRL 1066 in which CEO from non-PMSG-stimulated and PMSG-stimulated cynomolgus monkeys were cultured for 48 h. If the CEO were obtained from non-PMSG-stimulated m onkeys the hormones caused a significant cumulus expansion, but had on ly a limited effect on meiotic progression. However, if the CEO were o btained from PMSG-stimulated monkeys there was a significant stimulati on of cumulus expansion and meiotic progression. The hormone treatment resulted in a yield of 72.8% metaphase II oocytes compared with 40.9% in the controls.