Studies on the fractionation of diabetogenic extracts of the anterior pituitary gland

Abstract

The daily inj. of an alkaline extract of fresh ox ant. pituitary gland, prepared at low temp., from which the prolactin was removed, induced the symptoms of diabetes in dogs. The daily inj. of large doses of prolactin did not produce diabetes in dogs, even when prolactin was prepared from fresh glands at a low temp., under conditions which permit the preparation of active diabetogenic preparations. Neither prolactin nor the glycotropic ("anti-insulin") factor closely associated with, but distinct from it, was diabetogenic in intact dogs. The administration of prolactin to rabbits or monkeys did not induce a diabetic condition, although rabbits exhibited a transitory glycosuria. This transitory glycosuria cannot correctly be described as a diabetic condition since it was not accompanied by ketonuria or poly-uria. The daily administration of large amts. of partially purified thyrotropic hormone to dogs failed to induce a diabetic condition. The diabetogenic factor of the ant. pituitary gland is probably complex. The glycotropic and thyrotropic factors are possibly constituents of this complex, but prolactin is not.