IONIC AND OSMOTIC CONDITIONS 



73 



8 ZOj 



Fig. 6. Effect of pH on respiration and aerobic fructolysis of washed 

 spermatozoa in citrate-bicarbonate buffer. Number of sperm samples, n, 

 equals 8 (Cragle and Salisbury, 1959). 



mediate range, about pH 6.0, and is less at the extremes. Aerobic 

 glycolysis is linear and increases with pH, or with decreasing H ion 

 concentration. 



Such observations and the published literature suggest the tenta- 

 tive conclusion that oxygen consumption and the spermatozoan en- 

 zymes which control it are influenced much more by the other ions 

 than H ion concentration in semen and suspending fluids than is 

 glycolysis and the enzymes controlling it. Glycolysis is, on the other 

 hand, directly and linearly inhibited by H ion concentration below 

 the pH at which glycolysis is optimum. This point has not been 

 clearly established for any diluent, but is clearly at pH 8 or above 

 for the two media illustrated here. Thus, a working hypothesis can 

 be assumed to the effect that, other things being equal, pH of a re- 

 productive tract fluid will reflect the rate of spermatozoan activity 

 in it, both as to motility and energy exchange. In the absence of ade- 

 quate oxygen, control of metabolic exchange by manipulation of H 

 ion concentration is possible. The body probably does this and the 

 problem for optimum in vitro survival is to find optimum conditions 

 for inhibition and reversal of that inhibition. 



Combinations of Total Electrolytes, H Ion and K Ion Concentration 



Figure 7 shows the results of varying K+ concentration (at the ex- 

 pense of Na+) on aerobic metabolism of washed ejaculated bull 



