Nitric oxide synthase inhibitors prevent N-methyl-D-aspartic acid-induced penile erection and yawning in male rats.
The effect of NG-nitro-L-arginine methylester (NAME) and N-mono-methyl-L-arginine (NMMA), inhibitors of nitric oxide (NO) synthase on penile erection and yawning induced by N-methyl-D-aspartic acid (NMDA) injected in the paraventricular nucleus of the hypothalamus (PVN) was studied in male rats. NAME (75-150 micrograms) and NMMA (250-500 micrograms), but not N-monomethyl-D-arginine (D-NMMA)(250-500 micrograms) prevented both responses in a dose-dependent manner when given intracerebroventricularly (i.c.v.) 15 min before NMDA (50 ng). NMDA-induced penile erection and yawning was also prevented by the guanylate cyclase inhibitor methylene blue (200-400 micrograms i.c.v.), but not by the NO scavenger methemoglobin (50-100 micrograms i.c.v.). NAME (10-20 micrograms), but not Methylene blue or methemoglobin (10-20 micrograms), prevented NMDA-induced responses also when injected in the PVN 15 min before NMDA. The present results suggest that NMDA-induced penile erection and yawning is mediated by an increased NO synthesis in the PVN.
Melis
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Bernard B. Brodie Department of Neuroscience, University of Cagliari, Italy.
Stancampiano
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R
Argiolas
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D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016166:Free Radical Scavengers / Q000494:pharmacology; D007267:Injections; D008297:Male; D008706:Methemoglobin / Q000494:pharmacology; D008751:Methylene Blue / Q000008:administration & dosage / Q000494:pharmacology; D016202:N-Methylaspartate / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism; D019001:Nitric Oxide Synthase; D010286:Paraventricular Hypothalamic Nucleus / Q000187:drug effects / Q000201:enzymology; D010410:Penile Erection / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015000:Yawning / Q000187:drug effects*; D019323:omega-N-Methylarginine
D016166:Free Radical Scavengers; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D016202:N-Methylaspartate; D008706:Methemoglobin; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D008751:Methylene Blue; D019331:NG-Nitroarginine Methyl Ester