A nitric oxide synthase inhibitor, L-NAME, attenuates saccharin drinking in a two-choice test in water-deprived rats.
The nitric oxide synthase (NOS) inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) [0 (veh)], 10, 25, and 50 mg/kg s.c.) was administered to water-deprived, saccharin-preferring, rats in a 30-min two-bottle choice test of 0.1% sodium saccharin and tap water in a within subjects design. Saccharin intake was selectively attenuated in a dose-related manner with increasing dose of L-NAME, reaching statistical significance at 25 and 50 mg/kg L-NAME when compared to vehicle control condition (p < 0.01). In contrast, water intake was not appreciably affected. Total fluid intake was attenuated as well. Neither saccharin nor water intake in a second group of animals was significantly affected by the inactive isomer, D-NAME, suggesting a stereospecific action. These data suggest that a taste factor might contribute to the well-documented hypophagic action of NOS inhibitors in a number of animal species. The possibility that such effect might be mediated through a serotonergic mechanism is considered.
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Department of Psychology SC-454, Marquette University, Milwaukee, WI 53201-1881, USA.
D000704:Analysis of Variance; D000818:Animals; D002755:Choice Behavior; D004327:Drinking Behavior / Q000187:drug effects* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012201:Reward; D012439:Saccharin / Q000008:administration & dosage; D013549:Sweetening Agents / Q000008:administration & dosage; D013649:Taste / Q000187:drug effects* / Q000502:physiology; D014868:Water Deprivation / Q000502:physiology
D004791:Enzyme Inhibitors; D013549:Sweetening Agents; D019001:Nitric Oxide Synthase; D012439:Saccharin; D019331:NG-Nitroarginine Methyl Ester