Inhibitory effects of stress-activated nitric oxide on antioxidant enzymes and testicular steroidogenesis.
The messenger role of nitric oxide (NO) in immobilization stress-induced inhibition of testicular steroidogenesis has been previously suggested. In accord with this, here, we show that the intratesticular injection of isosorbide dinitrate (ISDN; 2x2.5 mg/testis), an NO donor, mimicked the action of stress on serum testosterone concentrations and hCG-stimulated testosterone production in rat testicular tissue. When added in vitro, ISDN inhibited testicular 3beta-hydroxysteroid dehydrogenase and 17alpha-hydroxylase/lyase. Immobilization stress and injections of ISDN also decreased the activity of catalase, glutathione peroxidase, glutathione transferase, and glutathione reductase in the interstitial compartment of testis. When stressed rats were treated concomitantly with bilateral intratesticular injections of N(omega)-nitro-L-arginine methyl ester, a non-selective NOS inhibitor (2x600 microg/testis), the activities of antioxidative enzymes, as well as serum testosterone concentration, were partially normalized. These results indicate that stress-induced stimulation of the testicular NO signalling pathway leads to inhibition of both steroidogenic and antioxidant enzymes.
Institute of Biology, Faculty of Sciences, University of Novi Sad, Dositeja Obradovica Square 2, 21000, Serbia, Novi Sad, Yugoslavia.
T S
TS
Kostic
S A
SA
Andric
D
D
Maric
R Z
RZ
Kovacevic
D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000037:antagonists & inhibitors; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000037:antagonists & inhibitors; D005980:Glutathione Reductase / Q000037:antagonists & inhibitors; D005982:Glutathione Transferase / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D007548:Isosorbide Dinitrate / Q000494:pharmacology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar; D013256:Steroids / Q000096:biosynthesis*; D013312:Stress, Physiological / Q000378:metabolism*; D013737:Testis / Q000187:drug effects / Q000378:metabolism*; D013739:Testosterone / Q000096:biosynthesis / Q000097:blood
D000975:Antioxidants; D006063:Chorionic Gonadotropin; D004791:Enzyme Inhibitors; D020030:Nitric Oxide Donors; D013256:Steroids; D009569:Nitric Oxide; D013739:Testosterone; D002374:Catalase; D005979:Glutathione Peroxidase; D019001:Nitric Oxide Synthase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D007548:Isosorbide Dinitrate; D019331:NG-Nitroarginine Methyl Ester