title: Effects of acute and chronic inhibition of nitric oxide synthase on brown adipose tissue thermogenesis.
abstract: This study was undertaken to examine the possible role of nitric oxide (NO) on brown adipose tissue (BAT) thermogenesis in rats. The chronic administration of N omega-nitro-L-arginine methyl ester (L-NAME; NO synthase inhibitor) in drinking water given to rats decreased interscapular BAT (IBAT) weight as well as DNA content in a warm environment (25 +/- 1 degrees C; 2 and 4 weeks), and inhibited the cold-stimulated (5 +/- 1 degrees C; 2 weeks) increase in IBAT weight and DNA content. L-Arginine administration (4 weeks in a warm environment) increased the DNA content of IBAT. Chronic L-NAME administration (2 weeks in a warm environment) eliminated the NE-stimulated increase in in vivo oxygen consumption (VO2), caused hypothermia in acute cold exposure (0 degree C), and suppressed the NE-stimulated increase in in vitro IBAT VO2. In vitro incubation of native IBAT with L-NAME suppressed the basal and NE-stimulated increase in in vitro VO2. In vitro incubation of IBAT with methylene blue (soluble guanylate cyclase inhibitor and a scavenger of free NO) eliminated the NE-stimulated increase in in vitro IBAT VO2. These results suggest that the nitric oxide and NO-cGMP signaling systems are involved in the regulation of BAT cellularity and thermogenesis in rats.
authors.affiliation: Department of Physiology I, Asahikawa Medical College, Japan.
authors.forename: S K
authors.initials: SK
authors.lastname: Saha
authors.forename: H
authors.initials: H
authors.lastname: Ohinata
authors.forename: A
authors.initials: A
authors.lastname: Kuroshima
mesh_terms: D002001:Adipose Tissue, Brown / Q000737:chemistry / Q000201:enzymology* / Q000502:physiology; D000818:Animals; D001120:Arginine / Q000378:metabolism; D001833:Body Temperature Regulation / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D008297:Male; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009569:Nitric Oxide / Q000502:physiology*; D019001:Nitric Oxide Synthase / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004791:Enzyme Inhibitors; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D019331:NG-Nitroarginine Methyl Ester