GONADOTROPIC SUBSTANCES 



tion is boiled. Askew and Parkes (1933) considered this to 

 be due to hydrolysis inasmuch as dry prolan readily with- 

 stood an hour's heating at 100° in the presence of oxygen. 

 According to von Euler and Zondek (1934), prolan resembled 

 enzymes as to the conditions (temperature and pH) under 

 which it was inactivated. It was also inactivated by ultra- 

 violet rays^* and by hydrogen peroxide, but not by a di- 

 peptidase. Fairly pure preparations of prolan do not contain 

 protein but they have usually been considered to resemble a 

 derived protein (e.g., a polypeptide). Prolan is said to be in- 

 activated by trypsin but not by pepsin (Reiss and Hauro- 

 witz, 1929; Wiesner and Marshall, 1931; and others). Good 

 preparations of prolan contain no amines, tyrosine (negative 

 Millon reaction), tryptophane (negative xAdarnkiewicz reac- 

 tion), adenine, phloroglucinol, halogen, sulphur, or phos- 

 phorus. The most potent preparations are said to contain 1-2 

 per cent histidine, 6 per cent arginine, and carbohydrate 

 equivalent to about 7 per cent glucose (C, 43 per cent, H, 

 6 per cent, O, 39 per cent, and N, 12 per cent)." 



THE FATE OF PROLAN IN THE ANIMAL BODY 



A few observations have been made on the fate of prolan 

 after its administration by various routes (also see pp. 178- 

 79). It is not surprising that prolan has little effect when ad- 

 ministered by way of the gastrointestinal tract. To produce 

 ovarian changes in mice 20-150 "units" had to be given by 

 stomach tube (Reiss and Haurowitz, 1929; Dickens, 1930). 

 According to Zondek (1929), and Huddleston and Whitehead 

 (1931), prolan per os also stimulated the gonads of immature 

 rats. They gave no data on dosage. 



After the intravenous administration of pregnancy-blood 

 to men or non-pregnant women (Ehrhardt, 1930; Ehrhardt 



3^ Also see Trettenero (1934). 



33 Fischer and Ertel (193O; Marshall (1932); Haurowitz, Reiss, and Balint 



(1933)- 



[223] 



