142 The Biochemistry of Semen 



animals. The following experiment was carried out by Mann, Davies 

 and Humphrey (1949) at the Agricultural Research Council Field 

 Station at Compton, in Berkshire. Six bull-calves were used. These 

 were castrated when one to two weeks old, i.e. at an age prior to the 

 appearance of fructose in the seminal glands. Seven months later 

 two of the castrated calves received subcutaneous implants of 0-5 g. 

 pellets of pure testosterone, whereas the remaining four were left 

 untreated. After another four weeks all six animals were sacrificed 

 and their seminal glands dissected out, weighed, and examined both 

 chemically and histologically. The unused portions of the hormone 

 pellets were recovered from the subcutaneous tissue of the two 

 hormone-treated calves; their weights were 0-344 and 0-338 g. 

 respectively, showing that the quantities of testosterone absorbed 

 per month per animal were 0- 1 56 and 0- 1 62 g., respectively. Chemical 

 analysis revealed the presence of considerable amounts of fructose 

 in the seminal glands in response to the four weeks' hormone treat- 

 ment (51 mg. fructose per 100 g. tissue or 5-3 mg. fructose per 

 total gland), as against a negligible fructose content in the untreated 

 castrates (8 mg. per 100 g. or 0-25 mg. per total gland). In compari- 

 son with and in contrast to the marked chemical difference, the 

 evidence for the functional recovery in the seminal glands, as 

 assessed by the histological examination, was practically impercep- 

 tible (Plate VI). In this way we were able to provide evidence that 

 the early effects of testosterone treatment can be established far 

 more convincingly by the large percentage-increase in the fructose 

 content of the seminal gland secretion, than by means of histological 

 methods which at this stage failed to show significant changes in the 

 glandular tissue. 



An investigation concerned with the response to testosterone was 

 also made by Rudolph and Samuels (1949) on rats, and by Gassner 

 and his co-workers (1952) on bulls. In castrated rats, a significant 

 increase in the fructose content of accessory organs was noticed 

 already ten hours after the injection of 1 mg. testosterone pro- 

 pionate. In bulls, fructose disappeared from ejaculates within two 

 weeks after castration but injections of testosterone propionate, if 

 given within four weeks after castration, led to a rapid return of 

 fructose production to the pre-castrate level; yet, in spite of the fully 

 restored fructose level, such seminal plasma, when added to washed 



