| Abstract: | The effect of various doses of pregnant mare's serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) on the yield of oocytes undergoing preovulatory maturation in organ culture was studied in mice. The mice received ip injections of .5, 1, 3, or 5 IU PMSG and 48 hours later, 0, 1, 2, or 4 IU HCC or their ovaries were cultured with 0, .2, .4, or .8 IU HCG/ml. 3-5 IU PMSG by 1-2 IU HCG induced maximum preovulatory response both in vivo and in culture. The proportion of large antral follicles with oocytes at Metaphase 2 was lower in culture than in the intact animal. However, the number of preantral and small Graafian follicles increased to a higher level in vivo and thus the overall total number of oocytes that progressed beyond the germinal vesicle stage was higher in organ culture. |
