EFFECTS OF HYPOTHALAMIC LESIONS AND SUBSEQUENT PROPYLTHIOURACIL TREATMENT ON PITUITARY STRUCTURE AND FUNCTION IN THE RAT1

Abstract

Introduction THERE is increasing evidence that many phases of anterior pituitary activity can be impaired by damaging either the hypothalamus or its neural or vascular connections with the hypophysis (Harris, 1948; Greer, 1952; Long, 1952). Our investigations were designed to relate functional alterations of the adenohypophysis produced in this way to concomitant morphological changes of the gland, the latter being examined by recently devised staining techniques which have considerably clarified the histophysiology of the pituitary in the rat (Purves and Griesbach, 1951a and Halmi, 1952a). We chose the use of hypothalamic lesions as a method of disrupting hypothalamic-hypophysial relationships since it presented two distinct advantages over infundibular stalk section. Firstly, it permitted localized destruction within the hypothalamus which we hoped might result in discrete effects on pituitary functions, and secondly, we believed that it would not be subject to the criticisms levelled at infundibular stalk section, a) that regeneration of the portal vessels may occur, nullifying the effect of the intervention (Harris, 1948)