Effect of chlorpromazine on bovine sperm respiration

Chlorpromazine (CPZ), an antipsychosis drug, causes the in vitro inhibition of sperm motility in various species, but the effect of this drug on sperm respiration is not well studied. This study was undertaken to evaluate the effect of this drug on ejaculated bovine sperm endogenous respiration. CPZ acted as a stimulator and an inhibitor of respiration at 0.1 and 0.75 mM CPZ, in the respiration medium, respectively. CPZ caused the release of sperm protein in the supernatant in a dose-dependent manner and the lactate dehydrogenase activity has also been demonstrated in the supernatant. Succinate and glycerol 3-phosphate supported the respiration among the respiratory substrates used in the present study, even after inhibition of endogenous respiration by 0.75 mM CPZ. Chlorpromazine has biphasic actions on bovine sperm respiration. The mechanism of action of the drug is discussed.