Squadrito F, Calapai G, Altavilla D, Cucinotta D, Zingarelli B, Campo G M, Arcoraci V, Sautebin L, Mazzaglia G, Caputi A P
Institute of Pharmacology, School of Medicine, University of Messina, Italy.
Neuropharmacology. 1994 Jan;33(1):83-6. doi: 10.1016/0028-3908(94)90100-7.
We studied nitric oxide (NO) synthase activity and serotonin content in the diencephalon of 24 hr food deprived rats. NO synthase activity was significantly increased whereas serotonin levels together with those of tryptophan and 5-hydroxyindoleacetic acid (5-HIAA) were reduced in food deprived rats when compared to control rats. NG-Nitro-L-arginine (L-NO Arg), an inhibitor of NO synthase, was used as a tool to study the role of NO in food deprivation. Twenty-four hr food deprived male Sprague-Dawley rats were intraperitoneally (i.p.) administered L-NO Arg (12.5, 25 and 50 mg/kg) before food presentation. Control rats received a NaCl (0.9%) solution. Food consumption was monitored 1 and 2 hr after food presentation. L-NO Arg administration produced a dose-dependent reduction in food intake. Pretreatment with metergoline (2 mg/kg) but not with ritanserin (1 mg/kg) antagonized the anorectic effect of L-NO Arg. Moreover, in the diencephalon L-NO Arg significantly reduced NO synthase activity whereas it increased serotonin levels. Our data indicate that NO might have a physiological role in the regulation of food intake and suggest that brain NO may modulate the central serotoninergic system.
我们研究了禁食24小时大鼠间脑中一氧化氮（NO）合酶活性和血清素含量。与对照大鼠相比，禁食大鼠的NO合酶活性显著增加，而血清素水平以及色氨酸和5-羟吲哚乙酸（5-HIAA）水平降低。NO合酶抑制剂NG-硝基-L-精氨酸（L-NO Arg）被用作研究NO在禁食中的作用的工具。在给禁食24小时的雄性Sprague-Dawley大鼠喂食前，腹腔注射（i.p.）L-NO Arg（12.5、25和50 mg/kg）。对照大鼠接受NaCl（0.9%）溶液。在喂食后1小时和2小时监测食物摄入量。给予L-NO Arg导致食物摄入量呈剂量依赖性减少。用美替拉酮（2 mg/kg）预处理可拮抗L-NO Arg的厌食作用，而用利坦色林（1 mg/kg）预处理则不能。此外，在间脑中，L-NO Arg显著降低NO合酶活性，而提高血清素水平。我们的数据表明，NO可能在食物摄入调节中具有生理作用，并提示脑内NO可能调节中枢血清素能系统。
