Aromatase gene expression in rat testicular cells in vitro

The ability of the male gonad to convert androgens into is well known; the microsomal enzymatic complex involved in this transformation is named aromatase and is composed of a specific cytochrome P450 aromatase (P450arom) and a ubiquitous reductase. Using a highly specific RT-PCR method we have measured the amount of P450arom mRNA in purified Leydig and Sertoli cells prepared from 20, 40 and 70-80 day-old rats. The amount of P450arom mRNA in the Leydig cells is independent of age (40 x 10(-3) attomoles/mu g of total RNA); in contrast in the immature rat Sertoli cells, after 5 days of culture the amount of P450arom mRNA is 20-fold lower when compared to that of 20-day-old rat Sertoli cells (71 x 10(-3) attomoles/mu g of total RNA). Nevertheless, irrespective of the age, the addition of either FSH or dbcAMP for dh increases the level of P450arom mRNA in the rat Sertoli cell preparations. Therefore, we evidenced that during testicular maturation not only the Leydig cells but also the Sertoli cells of the rat have the capacity to express the gene for cytochrome P450 aromatase.