Analysis of the phospholipid hydroperoxide glutathione peroxidase mRNA in the rat spermatozoon and effect of selenium deficiency on the mRNA.

Phospholipid hydroperoxide glutathione peroxidase (PHGPx) is a selenium (Se)-dependent glutathione peroxidase. It is reported that the relative PHGPx mRNA levels are much higher in the testis than in the other tissues. We have analyzed the existence and structure of the PHGPx mRNA in rat sperm and the changes in the level of the PHGPx mRNA after feeding with Se-deficient diets. We used 8-wk-old male Wistar strain rats given Se-adequate feed (control group, n = 5) and Se-deficient diets with marginal levels of Se (0.03 ppm or less) (Se-deficient group, n = 5) for 4 wk. The existence and level of the PHGPx mRNA in the cauda epididymal sperm, testis, and liver from the Se-adequate rats were analyzed by the reverse transcription-polymerase chain reaction and the Southern blotting method. As a result, the existence of the PHGPx mRNA was demonstrated in the cauda epididymal sperm as well as in the testis and liver. Moreover, the subtype of the PHGPx mRNA in the rat sperm was the mitochondrial-type mRNA, which included a region corresponding to the mitochondrial transfer leader sequence. These results imply that the intracellular localization of PHGPx may be regulated by the transcription level. On the other hand, there was no significant difference between the control group and the Se-deficient group in the Se level of the cauda epididymal sperm and the level of the PHGPx mRNA. In conclusion, it has been demonstrated that the PHGPx mRNA exists in rat sperm for the first time. The analysis of the PHGPx mRNA in the sperm would be a useful tool for investigating the disfunction caused by the disorder of the level or structure of the PHGPx in the sperm.