Fructose and Fructolysis 143 



spermatozoa obtained from a normal bull, was unable to support 

 sperm metabolism to the same extent as plasma from normal i.e. 

 non-castrated animals. 



An interesting example of the application of the fructose test to 

 problems of infertility in man has been provided by a study of four 

 eunuchoid patients who responded to androgenic treatment with a 

 highly significant elevation of fructose in semen (Landau and 

 Longhead, 1951). 



It seems probable that the fluctuations of fructose level in the 

 semen of normal individuals may also be due, in part at least, to 

 some periodic changes in the activity of the testicular hormone in 

 the male body. Normal rats, injected with large doses of the male 

 hormone invariably react by an increased level of fructose formation, 

 well above that of non-treated controls. The effect is particularly 

 striking with breeds of animals which exhibit a relatively low physio- 

 logical level of fructose formation. In this connection, however, it is 

 interesting to note that when injections of large doses of testosterone 

 propionate into normal rats are continued to excess, e.g. 200 i-ig. 

 daily for forty days, the state of overstimulation in the accessory 

 organs is accompanied by a marked decline in the size of the testes; 

 after seven weeks of such treatment the reduction in the weight of 

 the testes is nearly 50% (Mann and Parsons, 1950). Injections of 

 excessive doses of androgens are well known to produce harmful 

 effects on the spermatogenesis in animals and in man (Moore, 1939; 

 McCullagh and McGurl, 1939; Meckel, 1951). 



In normal bulls, a dose of 100 mg. testosterone propionate, 

 repeated three times weekly for six weeks, appears to produce only 

 a very slight increase in the level of fructose in semen (Gassner, 

 Hill and Sulzberger, 1952). However, according to another report, 

 sexual excitation prior to service has a stimulating effect on the out- 

 put of fructose in bull semen (Branton, D'Arensbourg and Johnston, 

 1952). 



(c) Hormone-induced formation of fructose in subcutaneous trans- 

 plants from accessory organs. Once the dependence of seminal fruc- 

 tose upon the activity of the male sex hormone had been established 

 it was possible to enquire into the mechanism of this hormonal rela- 

 tionship. One of the problems to settle was the extent to which the 

 process of fructose generation in accessory glands depends upon the 



