118 The Biochemistry of Semen 



used were a- and /3-phosphoglycerol, and phosphohexoses, chiefly 

 6-phosphoglucose and 6-phosphofructose, but also 1 : 6-diphospho- 

 fructose. More recently, however, other organic phosphoric acid 

 derivatives came into use, including various nucleotides and inter- 

 mediary phosphorylated compounds of glycolysis, as well as two 

 synthetic substances: phenylphosphate (King and Armstrong, 1934) 

 and phenolphthaleine phosphate (King, 1943; Huggins and Talalay, 

 1945). The introduction of histochemical techniques marked another 

 important development in studies on phosphatases (Gomori, 1939, 

 \94la, b, 1953). The histochemical investigations have thrown much 

 light upon the pattern of phosphatase distribution in the male 

 accessory organs and have helped to establish the existence of 

 'secretory' phosphatases, localized in the secretory epithelia and 

 secretions of accessory glands, as distinct from the 'stromal' phos- 

 phatases which are present only in the stroma (Dempsey, 1948; 

 Bern, 1949; RoUinson, 1954). 



''Acid' and 'alkaline' phosphatase 



An observation that the phosphatase activity of male urine is 

 usually higher than in women, led Kutscher and Wolbergs (1935) 

 to examine the phosphatase in semen and in the prostate gland. 

 They soon found that semen and prostate are among the richest 

 sources of acid phosphatase in the human body, the enzyme being 

 optimally active at pH 5-6, equally well towards a- and ^S-phospho- 

 glycerol, but largely inactive towards diphosphofructose and pyro- 

 phosphate (Kutscher and co-workers, 1936, 1938). Subsequent 

 investigations confirmed and extended these findings; the demon- 

 stration by Scott and Huggins (1942) that, while the voided urine 

 of man is rich in the enzyme, urine collected directly from the renal 

 pelvis shows only little enzymic activity, was a convincing proof 

 that the content of acid phosphatase in normally voided male urine 

 is due largely to the admixture of prostatic secretion. 



Acid phosphatase is an important secondary male sex charac- 

 teristic. Investigations by Gutman and Gutman (1938Z)) have shown 

 that the level of the enzyme in the human prostate is low in child- 

 hood but increases rapidly at puberty; thus the activity, expressed in 

 King- Armstrong units per gram prostate tissue, was H units at four 

 years of age, 73 units at puberty, and 522 to 2284 units in adult men. 



