THE PITUITARY BODY 



be separated by suitable methods; however, his views have 

 been given only in the form of an abstract. Although Cole 

 earlier believed that more than one gonadotropic principle is 

 present in pregnant-mare serum (e.g., Saunders and Cole, 

 1935), he later reported (1936) that he was unable to confirm 

 this belief. Also, Cartland and Nelson at no time secured 

 evidence of the presence of more than a single principle. For 

 purposes of discussion it will be assumed that there is but one 

 gonadotropic principle, although new work may support the 

 belief that a mixture of principles really is secreted. 



The slow metabolism of the hormone and the failure of the 

 kidneys to secrete appreciable amounts have already been 

 mentioned. In this connection the experiments of Catchpole, 

 Cole, and Pearson (1935) are of interest. The authors found 

 that about 50 per cent of the hormone disappeared from the 

 rabbit's blood 26 hours after intravenous injection (see Fig. 

 19). In the gelding the same proportion disappeared in 6 

 days. The hormone probably was destroyed, inasmuch as 

 none could be found in the urine or feces or in tissues such as 

 the uterus, lungs, kidneys, spleen, or liver. The rate of de- 

 struction was not affected by gonadectomy. 



Extract of the serum of pregnant mares stimulates the 

 gonads of male or female fowls. ■'^ In the immature cockerel 

 the homone causes testicular hypertrophy (without preco- 

 cious spermatogenesis) and a marked growth of the comb.^-^ 

 In immature females there is only moderate hypertrophy of 

 the ovary without ovulation but with marked growth of the 

 oviduct; the head furnishings are female in type. 



Cole (1936) as well as Hamburger (1936) investigated the 

 action of the hormone in both sexes of several species of mam- 



^'i Recent reports are those of Asmundson and Wolfe (1935), Hamburger (1936), 

 Uhl, Engelbreth-Holm, and Rothe-Meyer (1937), and Zavadowsky and others 

 (1937)- 



25 The cockerels used bv Zavadowsky and his colleagues were 50 days old. In- 

 jections of 50-200 mouse-units of the hormone for 20-40 days produced tremendous 

 comb growth, testicular hypertrophy, and spermatogenesis. Regression and even 

 degenerative changes appeared after long-continued administration of the hormone. 



[146] 



