134 R- J- FLIPSE 



Table I. Effect of buffer on pyruvate-alanine conversion by washed 

 bovine spermatozoa" 



Product Assayed 



Buffer 

 (counts per minute) 



Ringer Phosphate 



Ringer Phosphate- 

 5.0M Glycine (1:1) 



Alanine 1100 1645 



Pyruvate 1600 880 



"Data from Flipse and Anderson (1959). 



of the high glycine concentration to force the following reaction to 

 the right: 



Lactate ~^=^ Glycine + Pyruvate ~^ Glyoxylate + Alanine 



Regardless of whether this reaction actually accounts for the ob- 

 served extension of sperm livability, the results indicate that pyru- 

 vate is involved in sperm metabolism in more than the generally 

 recognized giycolysis-respiration pathway. 



This evidence of transamination in bovine semen prompted a 

 search for other transaminase systems (Flipse, 1960a). Routine chemi- 

 cal methods were used for glutamic-oxaloacetic transaminase and 

 glutamic-pyruvic transaminase, and both have been established as 

 components of bovine semen. In fact, the glutamic-oxaloacetic trans- 

 aminase level was found to exceed 600 units per milliliter of seminal 

 plasma — some twenty times the concentration in normal blood serum. 

 Additional assays revealed that the concentrations of both of these 

 transaminases were at least five times as high in the spermatozoa as in 

 seminal plasma. 



Evidence has been presented by Dr. Terner in this symposium of 

 the synthesis of diglycerides by spermatozoa. This is of considerable 

 interest to us, for we have observed synthesis in our amino acid 

 studies (Anderson and Flipse, 1959). Incubation of spermatozoa with 

 histidine-C 14 produced considerable activity in a compound which 

 we eventually identified as the dipeptide carnosine. One is prompted 

 to ask why synthesis occurs in these cells which are not subject to 

 growth or division. Are not such reactions wasteful of the energy 

 stores of the organism, and are they not likely to decrease survival 

 time? 



