Abstract
Spermatozoa from rats treated with 6-chloro-6-deoxyglucose (120 .mu.mol/kg per day) were as motile as those from controls soon after dilution but rapidly became immotile when 2 mM-pyruvate + 4 mM-DL-lactate rather than 2 mM-D-glucose was present and the former substrate allowed spermatozoa from treated rats to remain motile. The concentrations of the adenine nucleotides declined rapidly during 40 min incubations when the substrate was 2 mM-D-glucose. The ATP/ADP ratio and the energy charge (ATP + 1/2ADP/ATP + ADP + AMP) were maintained in spermatozoa from control rats but not in those from treated rats. When the substrate was 2 mM-pyruvate + 4 mM-DL-lactate adenine nucleotides were not lost as rapidly and there was less difference between spermatozoa from control and treated rats.