Cytochrome oxidase and lactate dehydrogenase activities in peroxidized rabbit epididymal spermatozoa

We report a quantitative cytochemical study on cytochrome oxidase and lactate dehydrogenase activities on rabbit epididymal spermatozoa during spontaneous lipid peroxidation. Our data show that during aerobic incubation both in NTP and KTP media the sperm cytochrome oxidase activity undergoes a significant decrease. The lactate dehydrogenase activity shows different cytochemical patterns in comparison between the two media considered. Such activity significantly increases in rabbit spermatozoa suspended in NTP medium from the first until the sixteenth hour of incubation time. At the following times the lactate dehydrogenase activity significantly declines showing yet until the later times of incubation integrated optical density values fairly high. During the whole period of the aerobic incubation, the spermatozoa suspended in medium KTP show lactate dehydrogenase integrated optical density values which not significantly differ from those of the control in spite of an initial enhancement from the first until the thirteenth hour of the experimental treatment.