Effect of Immunization with Estrone-Protein Conjugate in Rhesus Monkeys1

Abstract

Female rhesus monkeys were immunized with estrone-17-(O-carboxymethyl)oximebovine serum albumin. All 4 immunized monkeys developed circulating antibodies which bound radioactively labeled estrone and 17β-estradiol with equal affinity. All animals showed an increase in the plasma estrogen levels. The rate of disappearance of injected 3H-estradiol and its conversion to more polar metabolites was inhibited in the immunized animals. Two of the 4 animals became anovulatory as evidenced by low plasma progestin levels over an extended period. Ovulation and corpus luteum formation was successfully induced in the 2 anovulatory animals by the administration of human chorionic gonadotropin. It is concluded that the estrogen-dependent surge of luteinizing hormone necessary for the induction of ovulation does not occur in the anovulatory monkeys because the circulating antibodies bind the plasma estrogens and block their action. (Endocrinology93: 843, 1973)