Polidori C, Recchi S, Venturi F, Ciccocioppo R, Massi M
Department of Pharmacological Sciences and Experimental Medicine, University of Camerino, Italy.
Peptides. 1998;19(9):1557-64. doi: 10.1016/s0196-9781(98)00112-0.
Tachykinin NK-3 receptor agonists reduce alcohol intake in alcohol-preferring rats; the nucleus basalis magnocellularis (NBM) is highly sensitive to their effect. Tachykinins and their receptors are widely distributed in gustatory pathways and NK-3 receptor agonists have been reported to modify taste reactivity to salt solutions in rats. The present study evaluated whether the TK NK-3 receptor agonist aminosenktide (NH2-SENK) influences taste reactivity to ethanol solutions. Genetically selected Marchigian Sardinian alcohol-preferring (msP) rats were employed. In response to the intraoral infusion (0.8 ml in 1 min) of 10, 20, 40, or even 60% ethanol solution, ethanol-naive rats showed a large number of ingestive reactions and a much lower number of aversive reactions. Two min before the intraoral infusion of 10 or 40% ethanol, NH2-SENK was injected either into the lateral ventricle (LV) or into the NBM. Doses of NH2-SENK that markedly reduce alcohol intake, 125 ng/rat into the LV or 5 ng/site into the NBM, did not modify the ingestive reactions and, in some instances, reduced the aversive reactions to ethanol solutions in ethanol-naive rats. Injections of 125 ng/rat into the LV failed to modify taste reactions in ethanol-experienced rats. The present results show that msP rats have an innate hedonic evaluation of ethanol solutions, even of high concentration. Moreover, they indicate that reduction of ethanol intake induced by TK NK-3 receptor agonists in alcohol-preferring rats does not depend on influences on gustatory processes.
速激肽NK - 3受体激动剂可减少偏爱酒精大鼠的酒精摄入量；大细胞基底核（NBM）对其作用高度敏感。速激肽及其受体广泛分布于味觉通路中，并且据报道NK - 3受体激动剂可改变大鼠对盐溶液的味觉反应。本研究评估了速激肽NK - 3受体激动剂氨基速激肽（NH2 - SENK）是否会影响对乙醇溶液的味觉反应。采用了基因选择的马尔基安撒丁岛偏爱酒精（msP）大鼠。对于初次接触乙醇的大鼠，经口内输注（1分钟内输注0.8 ml）10%、20%、40%甚至60%的乙醇溶液后，它们表现出大量的摄取反应和数量少得多的厌恶反应。在经口内输注10%或40%乙醇前两分钟，将NH2 - SENK注入侧脑室（LV）或NBM。显著减少酒精摄入量的NH2 - SENK剂量，即注入LV的剂量为125 ng/只大鼠或注入NBM的剂量为5 ng/位点，并未改变摄取反应，并且在某些情况下，减少了初次接触乙醇的大鼠对乙醇溶液的厌恶反应。向LV内注射125 ng/只大鼠未能改变有乙醇接触经验的大鼠的味觉反应。目前的结果表明，msP大鼠对乙醇溶液，甚至是高浓度乙醇溶液具有先天性的享乐评价。此外，这些结果表明，速激肽NK - 3受体激动剂在偏爱酒精的大鼠中诱导的乙醇摄入量减少并不取决于对味觉过程的影响。
