Further Investigations Concerning the Stimulating Effect of Anterior Pituitary Gland Preparation on the Thyroid Gland.

Abstract

We have shown that while feeding of Armour's tablets of anterior pituitary has an inhibiting effect on the activity of the thyroid gland as indicated by the structural changes it induces, injections of acid or alkaline extracts of anterior pituitary prepared in our own laboratory from cattle gland have a very markedly stimulating effect, comparable to that characteristic of the thyroid in typical Graves'disease. We furthermore compared with the effects of the extracts, the effects of inoculation of anterior pituitary gland substance as such, obtained from guinea pig, rabbit, or cattle. These investigations suggested the conclusion that there are apparently several active substances in the anterior pituitary and that the substance responsible for the growth of the ovarian follicle and ovulation is not identical with the substance responsible for the hypertrophy of the thyroid gland, but that the latter seems to be identical with the substance which causes the production of interstitial gland and of pseudolutein bodies in the ovary of the guinea pig. Silberberg has shown that if acid extract of anterior pituitary and KI, both of which given singly stimulate the thyroid gland, are administered simultaneously, not only is there a lack of summation of the stimulating effects exerted by these substances, but a diminution of the hypertrophy which otherwise would have been caused by acid extract of anterior pituitary alone. We now report on the continuation of our investigations into the relation between the anterior pituitary and thyroid glands.