Ionic Balance of Sperm Cells 



H. B. STEINBACH and PHILIP B. DUNHAM 



Department of Zoology, University of Chicago, Chicago, Illinois 



As you all know, conduction of nerve impulses and irritability in 

 general are strongly associated with ion gradients, usually an out- 

 wardly directed potassium gradient, and an inwardly directed so- 

 dium gradient. All sorts of special pumps, binding mechanisms, and 

 physiological gremlins have been postulated to account for this 

 ubiquitous condition of all cells. 



Unfortunately, ion gradients are so general in type and occurrence 

 that it has been very difficult to decide just what physiological func- 

 tion causes the gradients and which functions depend upon them. It 

 seems fairly clear that response to stimulation involves the energy of 

 the gradient; presumably some metabolic system keeps the mecha- 

 nism going. 



It occurred to us that the nicely compartmentalized spermatozoon 

 might provide some answers; there is here such a clear separation of 

 the mobile, conductile tail, the metabolic midpiece, and the informa- 

 tion-storage head. Furthermore, the compartments can be simply 

 shaken apart and examined separately. We did just that and shall re- 

 port some of the findings to you. [See Steinbach and Dunham (1961) 

 for complete report.] 



The general procedure was to collect sperm of three animals, A rba- 

 cia, Mytilus, and Phascolosoma, and treat them with appropriate 

 solutions, usually sea water or mixtures of sea water and other solu- 

 tions. We found we could easily fragment all three types of sperm 

 into head-midpiece fractions and tail fractions by a few seconds 

 treatment in a Waring Blendor, followed by orthodox differential 

 centrifugation. Rather than make cell counts — after all we are both 

 physiologists — we treated most samples with C 14 -inulin to measure 

 extracellular space. Centrifuged pellets of whole sperm, head mid- 

 pieces, and tails were then analyzed by routine methods. 



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