Functional Pituitary Grafts in Rats

Abstract

Recent experiments by Hohlweg and Junkmann, 1 Haterius, Schweizer and Charipper, 2 and Hill and Gardner 3 have indicated quite conclusively that pituitary tissue will function as a graft.

It is the purpose of this report to present summarily a series of experiments in which the empty sellae of hypophysectomized 28-day-old male and female rats were utilized immediately after the operation as sites for grafting pituitary tissue. The types of grafts included: 1. male hosts bearing (a) their own pituitaries as grafts and (b) the pituitaries of 28-day-old female rats; 2. female hosts bearing (a) their own pituitaries as grafts (b) the pituitaries of other 28-day-old female rats (c) the pituitaries of 1 to 5 newborn male rats; (d) the pituitaries of male rats 20 to 40 days old. Hosts and donors were taken from an intensively inbred strain of rats. In a group of 37 such hosts (5 males and 32 females) which were observed for 14 weeks, 73% takes occurred as judged by marked body growth and attainment of a functional sexual capacity.† The growth curves of these animals ascended much more gently and flattened out at one-half to two-thirds the heights of similar curves for normal non-hypophysectomized controls.

The sexual development and history of the grafted females were similar in all groups regardless of the source of the transplanted tissue. Vaginal smears and exploratory examinations of the ovaries established the fact that typical cyclic oestrous phenomena occurred. The cycles in different animals varied in length from 4 to 14 days, the majority having a 5- to 7-day rhythm. The elongated cycles were due in every instance to a prolonged dioestrous interval. Ovulation was spontaneous and the resultant corpora lutea appeared normal. Thirteen pregnancies were recorded, 8 occurring among the females bearing male pituitaries. Living young were delivered at term and lactation was normal.