20 The Biochemistry of Semen 



acids in protein-free filtrates of ground prostatic adenoma or dog 

 prostate, expressed in terms of millimoles/100 g. tissue, is 34 and 

 39, respectively. The ventral lobe of the rat prostate contains in a 

 free state nearly all known amino acids, and in addition phosphoryl- 

 ethanolamine, taurine, glutathione, and glutamine. The dorso-lateral 

 lobe on the other hand, in contrast to the ventral prostate, has a 

 much lower content of most amino acids and lacks completely iso- 

 leucine and threonine; it may be added here that it also responds 

 differently to castration and to hormones. 



The seminal vesicle secretion (Tables 2 and 3) 



In several species, including the rat, guinea-pig and bull, the 

 seminal vesicles alone contribute more fluid than the rest of the 



Table 2. Some characteristic constituents of the seminal vesicle 

 secretion in man, bull, boar, rat and guinea-pig 



(In each species, two individuals were examined, and results expressed 

 as averages (mg./lOO ml.); the human vesicular secretion may have been 

 contaminated with prostatic fluid. Ascorbic acid was determined as dinitro- 

 phenylhydrazone, and the value represents the sum of the oxidized and 

 reduced form.) 



* In rat, fructose is secreted by the coagulating gland, an organ adjacent 

 to the seminal vesicle (see Fig. 4). 



accessory glands together. Whereas however, in the rat and guinea- 

 pig the seminal vesicles conform to the pattern of true thin-walled 

 and large 'vesicles', the bull seminal vesicles are more correctly des- 

 cribed as seminal 'glands', with multiple lobes of glandular tissue 

 which surrounds a system of ramified secretory ducts. The size and 

 storage capacity of the seminal vesicles, and their secretory output, 



