388 



PHYSIOLOGY OF GONADS 



and plasma of human semen remains to be 

 determined. 



Citric acid. Citric acid was first detected 

 in human semen by Schersten (1929). The 

 distribution of citric acid in the semen and in 

 the secretions of the accessory glands of var- 

 ious species is summarized in Table 6.5. In 

 some animals, {e.g., the rat and man), citric 

 acid is produced mainly by the prostate 

 gland, and in others {e.g., the bull, boar, and 

 guinea pig), most of it originates from the 

 seminal vesicles. 



The citric acid content of the seminal 



plasma and of the secretions of accessory 

 glands depends on androgenic hormones. 

 Citric acid disappears from these fluids after 

 castration, and is formed again after treat- 

 ment with testosterone. This ''citric acid 

 test" has been used to determine the time of 

 onset of secretory function in accessory 

 glands (Mann, Davies and Humphrey, 1949; 

 Ortiz, Price, Williams- Ashman and Banks, 

 1956), hormonal influences on secretion in 

 subcutaneous transplants (Mann, Lutwak- 

 Mann and Price, 1948; Lutwak-jNIann. 

 Mann and Price, 1949 L the androgenic ac- 



TABLE 6.5 



Citric acid in semen and in the secretions of accessory reproductive glands 



