The production of antisera to preparations of prolactin containing the glycotropic (anti-insulin) factor of the anterior pituitary gland

Abstract

Large doses of ox prolactin possessing no detectable thyrotropic activity were administered daily to rabbits and monkeys for long periods. The serum of animals so injected for 12 wks. or more possessed marked ability to prevent the hypertrophic response of the pigeon crop gland to prolactin. The avg. wt. of the young reared by lactating mice which received daily injs. of rabbit antiserum was slightly, but probably significantly, less than that of the young of control animals receiving similar injs. of normal serum. This was possibly due to partial inhibition of milk secretion in those animals receiving antiserum. Rabbits which had received daily injs. of prolactin for 18 wks. exhibited a normal hypoglycemic response to insulin after the administration of a potent pituitary glycotropic prep., i. e., they were insensitive to the glycotropic action of the extract. No evidence was found that this resistance to the glycotropic action of pituitary preps. was transmissible to normal animals by the serum of the resistant rabbits. Although the prolactin used to prepare the sera contained no detectable thyrotropic activity, the antiserum obtained from the rabbits possessed substantial antithyrotropic activity, i. e., ability to induce hypertrophy of the thyroid of immature guinea pigs.