A nitric oxide synthase inhibitor, N(G)-nitro-L-arginine methyl ester, attenuates lipoprivic feeding in mice.
Possible involvement of nitric oxide (NO) in lipoprivic feeding was investigated in nondeprived male ICR mice adapted to a high-fat diet in a within-subjects design. Lipoprivation was induced by blocking fatty acid oxidation with Na-mercaptoacetate (MA), which produces a short-term increase in feeding in mice and rats. Food intake, measured at 1, 2, and 4 h following injection of 70 mg/kg of MA, was attenuated in a dose related manner with increasing pretreatment dose (1,10, 25 and 50 mg/kg sc) of the NO-synthase (NOS) inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), reaching statistical significance at 10 mg/kg of L-NAME at h1 when compared to vehicle control condition. The inactive isomer, D-NAME, was ineffective, thereby supporting stereospecific drug action and directly implicating NO. A control experiment measured general locomotor activity (grid crossings and rears) in an open arena under 10-50 mg/kg of L-NAME in the same mice; both measures were significantly different from vehicle condition only at the highest dose. These findings support involvement of NO in lipoprivic hyperphagia; they are consistent with and extend research linking NO and ingestive behaviors through use of NOS inhibitors. Possible influences of confounds were discussed.
Biopsychology Laboratory, Department of Psychology, Marquette University, SC-454, P.O. Box 1881, Milwaukee, WI 53201-1881, USA. donald.czech@marquette.edu
Donald A
DA
Czech
Melanie R
MR
Kazel
John
J
Harris
D000818:Animals; D004041:Dietary Fats / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology*; D008055:Lipids / Q000502:physiology; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009043:Motor Activity / Q000187:drug effects; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology*; D009569:Nitric Oxide / Q000502:physiology*
D004041:Dietary Fats; D004791:Enzyme Inhibitors; D008055:Lipids; D009569:Nitric Oxide; D019331:NG-Nitroarginine Methyl Ester