ARACHIDONIC-ACID METABOLITES AS INTRATESTICULAR FACTORS CONTROLLING ANDROGEN PRODUCTION

The effect of inhibitors and products of arachidonic acid metabolism o n rat testicular steroidogenesis has been investigated. In the presenc e of indomethacin (inhibitor of cyclooxygenase) and nordihydroguaiaret ic acid (NDGA) (inhibitor of lipoxygenase), the activity of 3beta-hydr oxysteroid dehydrogenase (3beta-HSD) and 17beta-hydroxysteroid dehydro genase (17beta-HSD) were both inhibited. The LH-stimulated increase in secretion of testosterone and progesterone was also inhibited by indo methacin and NDGA. On the other hand, vitamin E (antioxidant and inhib itor of lipoxygenase), stimulated the activity of both 3beta-HSD and 1 7beta-HSD and enhanced LH-stimulated androgen production. The metaboli tes of lipoxygenase (1 5-HPETE, 15-HETE, 5-HPETE and 5-HETE) and cyclo oxygenase (PGF2alpha) pathways stimulated 3beta-HSD and 17beta-HSD act ivity and enhanced the secretion of progesterone and testosterone. It is concluded that arachidonic acid matabolites are intratesticular fac tors which can regulate LH-stimulated testicular steroidogenesis.