Effects of 6-chloro-6-deoxysugars on glucose oxidation in rat spermatozoa

6-Chloro-6-deoxyfructose or 6-chloro-6-deoxyglucitol (greater than 90 mumol/kg/day), 6-chloro-6-deoxyglucose or 6-chloro-6-deoxymannose (greater than 120 mumol/kg/day) and 6-chloro-6-deoxygalactose (greater than 300 mumol/kg/day) all had an antifertility action in the male rat when given by mouth. Spermatozoa from the infertile rats were unable to oxidize glucose. This effect was always produced by a lower dose than the antifertility effect and the threshold dose for the 2 effects varied in a parallel fashion between the different 6-chloro-6-deoxysugars. Glucose oxidation appeared to be inhibited at the triose phosphate isomerase or glyceraldehyde 3-phosphate dehydrogenase reaction. These effects of 6-chloro-6-deoxysugars are similar to those of alpha-chlorohydrin. The activities of the glycolytic enzymes were greatly in excess of the observed flux through the pathway and high concentrations of glucose 6-phosphate and triose phosphate accumulated in rat spermatozoa incubated with 2 mM-D-glucose.