Effect of inhibin on ovulation and implantation in mice.

Injection of antiserum to ovine FSH on the day of proestrus could inhibit ovulation in the next cycle. Inhibin preparation purified from sheep ovaries failed to affect ovulation in mice. Suppression of FSH by this preparation of inhibin during early pregnancy reversed the mitotic index. Administration of inhibin during the peri-implantation period terminated pregnancy in mice. The inhibin preparation decreases FSH in circulation which in turn may possibly reduce ovarian estrogens, thereby inhibiting pregnancy.