Fructose and Fructolysis 



141 



fructose and citric acid appear in the accessory glands at an early 

 age, before there is any evidence of active spermatogenesis; since 

 the secretion of both these substances depends upon the presence of 

 the male sex hormone, it must be concluded that the hormone 

 begins to function in the male body well in advance of the actual 

 spermatogenesis. Thus, for instance, in bull-calves appreciable 



5 25 50 



Daily dose of testosterone propionate (/ig.) 



Fig. 13. Dosage-response curves of testosterone propionate, using the coagu- 

 lating glands of the rat; -O, fructose (/^tg.); • •, 



weight of organs (mg.). 



(Mann & Parsons, 1950) 



amounts of fructose are found in the vesicular secretion already at 

 the age of about four months, whereas the first mature spermatozoa 

 appear nearly eight months later. One cannot, of course, rule out 

 the possibility that the testicular hormone is active in the bull-calf 

 even before the age of four months, but if so, then either its con- 

 centration is too small to produce a distinct response in the accessory 

 organs, or else its action is countered by some other factors. 

 ib) Effect of testosterone on the appearance of fructose in castrated 



