90 



CHARLES TERNER 



None 

 Pyruvate 

 Pyruvate, DNP 



18.1 

 25.9 

 25.8 



45.6 

 8.0 



24.0 

 0.6 



21.6 



7.4 



"Washed spermatozoa incubated in phosphate saline at 37°; gas, air; pyruvate, 

 0.01M; DNP, 10~ 4 M ; incubation period 45 min; sperm count 9.7 X 10 s /vessel. 



aerobic breakdown of carbohydrate in spermatozoa. In bull spermato- 

 zoa incubated with glucose or fructose, the addition of DNP results, 

 as in other animal tissues, in stimulation of the rate of respiration and 

 also of the rate of accumulation of lactic acid under aerobic condi- 

 tions (Melrose and Terner, 1953). 



At a later stage the adoption of a more convenient technique dis- 

 pensed with the tedious analytical determinations. By using C 14 - 

 labeled substrates, the respiratory C0 2 can be collected, and its ra- 

 dioactivity provides a measure of the amount of substrate oxidized. 

 Table II shows that of glucose, acetate, and pyruvate, the last was 

 oxidized most readily, which would not have been apparent from 

 measurements of the oxygen uptake alone. Also the different types 

 of responses to DNP of spermatozoa metabolizing pyruvate or car- 

 bohydrate are shown. The formation of lactate from pyruvate by 



Table II. Metabolism of acetate, pyruvate and glucose in bull spermatozoa" 



Labeled Substrate 

 Appearing in Respir- 

 atory C0 2 Gul/10 8 

 spermatozoa/hr) 



Additions 



Z , 



None 

 DNP 



l-C 14 -acetate 

 l-C 14 -acetate, DNP 

 3-C 14 -pyruvate 

 3-C 14 -pyruvate, DNP 



C 14 -glucose 



C 14 -glucose, DNP 



" Washed spermatozoa incubated in phosphate saline at 37°; gas, air; l-C 14 -ace- 

 tate, O.OlAf ; 3-C 14 -pyruvate, 0.01A/; C u -glucose (r.L), 0.005M; DNP, lQr i M; incuba- 

 tion period, 90 min; sperm count, 9.42 X 10 8 /vessel. 



