EFFECT OF PURIFIED GONADOTROPES ON THE ANDROGEN-SECRETING ABILITY OF TESTES OF HYPOPHYSECTOMIZED COCKS1

Abstract

Using hypophysectomized cocks as test animals, it was found that prepns. of FSH which are absolutely free from LH will not cause enlargement of the capon-like comb of the completely hypophysectomized cock. Such an FSH will cause considerable increase in testes size which is largely due to increase in tubular tissue. LH alone causes both comb growth and enlargement of the testes. FSH contaminated even with small amts. of LH will cause both comb growth and increase in testes wt. There is a synergistic effect between these 2 hormones. The hypophysectomized cock is well suited to serve as a test animal for the detn. of the purity of FSH prepns. Even small amts. of LH, when admixed to an FSH prepn., can be detected by causing the disappearance of the characteristic pallor of the head region of the hypophysectomized cock. Larger amts. of LH will be detected by measurable increases in comb size. The completeness of the operation is never in doubt, since even minute remnants of pituitary tissue will prevent complete regression of the comb following hypophysectomy or will cause enough androgen to be secreted to give the head region a red or "flushed" appearance. The results obtained further increase the evidence in favor of the Leydig cells as the source of androgen. Large doses of chorionic gonadotrophin, contrary to most recent work, but in agreement with earlier studies, do not have any measurable biologic effect in either the immature intact chick or the hypophysectomized cock.