Lack of Effect of Theelin upon Somatogenic,Thyreotropic,and Adrenotropic Activity of Hypophysis

Abstract

It has been well established that rats treated with theelin undergo a diminution in the sex-stimulating power of the hypophysis. 1 , 2 , 3 Nelson 4 has recently demonstrated changes in the basophilic cells of the hypophyses of rats following injection of theelin which he interprets as indicating inhibition of secretory activity. Similar findings are recorded by Halpern and D'Amour. 5 The same changes are described in the pituitaries of rats treated with pregnancy-urine extracts, 4 , 6 , 7 , 8 and these alterations are interpreted as secondarily due to increased secretion of the gonadal hormone. 4 , 6 , 7 , 9 There is some disagreement as to the changes in the acidophilic cells. Nelson 4 records a decrease in the number of normal cells, with degranulated forms. Severinghaus 7 finds little change in immature females, a reduction in number, size, and staining reaction in adult females and an increase in number, size, and staining reaction in adult males. Wolfe 8 describes an increase in infantile females. Barnes, Reagan, and Nelson 10 have demonstrated that in depancreatized dogs the injection of theelin has a similar effect to that of total hypophysectomy. Nelson and Overholszer 11 have recently reported confirmatory experiments in depancreatized monkeys.

Since the initial work indicates very strongly that the administration of theelin has an inhibitory effect upon the histological picture of the anterior lobe of the hypophysis and suppresses its sex-stimulating power and diabetogenic activity, it seemed worth while to investigate any possible influence it might have upon the other anterior pituitary effects, somatogenic, thyreotropic, and adrenotropic.

Litter-mate rats were divided into 3 groups. Group A, consisting of 3 males and 3 females, received daily injections of 9 rat units of theelin∗ in oil (0.03 cc.). Group B, comprising the same number of animals, was treated with injections of an equal quantity of Mazola oil. Group C, 2 males and 2 females, served as untreated controls. Injections were made daily from the 23d to the 90th day of life.