EFFECT OF VARIOUS STEROIDS ON THE DEVELOPMENT OF THE BURSA FABRICII IN CHICK EMBRYOS1

Abstract

The effects of various androgen-like steroids on the development of the bursa of Fabricius, the thymus and spleen were studied in chick embryos. Varying doses of the hormones, ranging from 0.05 mg. to 1.5 mg., were injected in oil solution into the albumin portion of developing eggs on the 5th day of incubation. Autopsies were performed on the 19th day of incubation. Of the compounds tested, dihydrotestosterone proved to be the most active in terms of inhibiting the development of the bursa, using the degree of reduction of the tissue weight as the criterion of activity. Several of the other less potent compounds were grouped in the order of decreasing activity as follows: a) androsterone, androstane-3,17-dione, b) 19-nortestosterone, testosteronecyclo- pentyl-propionate, methylandrostenediol, and c) testosterone. An attempt was made to relate the relative activities of these compounds in causing bursal inhibition to their structural configurations. For example, those androgens with a completely reduced s...