title: In vitro studies on histochemical localization of testicular delta5-3beta-hydroxysteroid dehydrogenase activity from indomethacin pretreated rats--effect of prostaglandins and luteinizing hormone.
abstract: In vitro studies on the effect of LH and prostaglandins on delta5 3beta-hydroxysteroid dehydrogenase activity using indomethacin pre-treated testis as the experimental model, revealed a greater stimulation of the enzyme activity when the incubation medium contained LH and PGE2 both at a concentration of 1 microgram/ml in comparison to the effect produced by 1 microgram LH/ml alone, but the augmentory effect of PGE2 on testicular response to LH was not evidenced as the LH: PGE2 ratio became 1 : 10. Neither PGE2 nor PGF2A produced any stimulation of the enzyme activity at concentrations of 1, 10, or 20 microgram/ml in the incubating medium. PGF2A at concentrations of 1 or 10 microgram/ml did not appear to interfere with LH action on this steroidogenic enzyme. On the contrary, prostaglandins, both PGE2 and PGF2A, at concentrations of 20 microgram/ml, antagonized LH action over testicular delta5-3beta-hydroxysteroid dehydrogenase activity. On the basis of these findings, it appears that prostaglandin E2 in some way, is necessary for manifestation of the steroidogenic action of LH in testis.
mesh_terms: D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D004357:Drug Synergism; D004789:Enzyme Activation / Q000187:drug effects; D006651:Histocytochemistry; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology*; D007986:Luteinizing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008297:Male; D011459:Prostaglandins E, Synthetic / Q000008:administration & dosage / Q000494:pharmacology*; D011461:Prostaglandins F, Synthetic / Q000494:pharmacology*; D051381:Rats; D013737:Testis / Q000201:enzymology*
chemical_list: D011459:Prostaglandins E, Synthetic; D011461:Prostaglandins F, Synthetic; D007986:Luteinizing Hormone; D015096:3-Hydroxysteroid Dehydrogenases; D008058:Dihydrolipoamide Dehydrogenase; D007213:Indomethacin