A TECHNIQUE FOR HYPOPHYSECTOMY OF THE RAT

Abstract

The hypophysectomized rat has become of great value as a test animal in studies of the pituitary gland and its relations to the other organs of internal secretion. To be of greatest usefulness, a large number of these animals is desirable. However, in our attempts to product a colony of hypophysectomized animals the available descriptions proved inadequate, and it was found necessary to modify the various techniques in order to develop an operation which was simple and rapid, and yet which totally removed the gland. The need for large numbers of these test animals seems to justify the following detailed account of the procedure, which aims to remove the anterior and posterior lobes of the hypophysis, leaving the pars tuberalis, the pituitary stalk, and the diaphragma sellae intact. Phillip E. Smith (4), in 1930, described a parapharyngeal approach for hypophysectomy of the rat, and in the same year Richter and Wislocki (3) suggested improvements in the method. Recently Koyama (2) has published an ingenious method for aspiration of the hypophysis by a needle inserted through the auditory canal. However, when one recalls how difficult it is at times to secure complete ablation under direct observation, one suspects that such blind aspiration may frequently leave a pituitary residue, which will lead to inconstant experimental results.