Cellular localization and age dependent changes in mRNA for glutathione S-transferase-P in rat testicular cells

Using Northern blotting techniques we report that mRNA for Glutathione S-transferase-P (GST-P or GST 7-7) is present in rat testis. GST-P mRNA was detected in cultured Sertoli cells, cultured peritubular cells, as well as in transplantable Leydig cell tumor. However, no GST-P mRNA was detected in rat germ cell fractions. There was a marked increase in mRNA for GST-P from day 5 to day 20 in rats, after which a decrease was seen. The decreased level of mRNA for GST-P in the testis after 20 days of age, coincided in time with the exponential increase in germ cells, and accompanying relative decrease in somatic cells. The results show that mRNA for GST-P is primarily present in somatic cells of the rat testis.