Nava F, Calapai G, Facciolà G, Cuzzocrea S, Giuliani G, De Sarro A, Caputi A P
Institute of Pharmacology, School of Medicine, University of Messina, Italy.
Eur J Pharmacol. 1997 Jul 23;331(2-3):267-74. doi: 10.1016/s0014-2999(97)01049-2.
In 24 h water deprived rats we have evaluated the effects of melatonin on the inhibition of thirst and on fever induced by Escherichia coli lipopolysaccharide. Intraperitoneal (i.p) injection of lipopolysaccharide (0.32, 0.64 and 0.96 mg/kg) alone induced, a dose-dependent and significant inhibition of water intake as well as fever. In addition, lipopolysaccharide at the same concentrations increased urinary prostaglandins and serum cytokines levels. On the contrary, lipopolysaccharide treatment had no effects on cerebral brain nitric oxide synthase activity. All lipopolysaccharide effects were reverted by a prior, concomitant and subsequent i.p. treatment with melatonin (2, 4 and 6 mg/kg), whereas they were still present when melatonin was injected in combination with the melatonin receptor antagonist luzindole (15, 30 and 60 mg/kg, i.p.). We suggest that melatonin could exert its dipsogenic effects through a reduction of the free radical nitric oxide (NO.) whereas it may reduce body temperature by preventing an excessive formation of prostaglandins and cytokines.
在24小时缺水的大鼠中，我们评估了褪黑素对抑制口渴以及对大肠杆菌脂多糖诱导的发热的影响。单独腹腔注射脂多糖（0.32、0.64和0.96毫克/千克）会引起饮水的剂量依赖性显著抑制以及发热。此外，相同浓度的脂多糖会增加尿中前列腺素和血清细胞因子水平。相反，脂多糖处理对脑内一氧化氮合酶活性没有影响。所有脂多糖的作用都可通过预先、同时及随后腹腔注射褪黑素（2、4和6毫克/千克）而逆转，而当褪黑素与褪黑素受体拮抗剂鲁辛朵（15、30和60毫克/千克，腹腔注射）联合注射时，脂多糖的作用仍然存在。我们认为，褪黑素可能通过减少自由基一氧化氮（NO.）发挥其致渴作用，而它可能通过防止前列腺素和细胞因子的过度形成来降低体温。
