Effect of microinjection of histamine into the dorsal hippocampus on the orofacial formalin-induced pain in rats
Effect of microinjection of histamine into the dorsal hippocampus on the orofacial formalin-induced pain in rats
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DOI：
10.1016/j.ejphar.2009.10.063
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发表时间：
2010-02-10
影响因子：
5
通讯作者：
Khalilzadeh, Emad
中科院分区：
文献类型：
--
作者：
Erfanparast, Amir;Tamaddonfard, Esmaeal;Khalilzadeh, Emad
脑神经元组胺通过其受体参与中枢疼痛感知。在大鼠口面疼痛模型上，研究了背侧海马内微量注射组胺、组胺H-1受体拮抗剂美托咪胺和组胺H-2受体拮抗剂雷尼替丁的作用。口面疼痛诱导皮下注射福尔马林（1%，50 μ l）在大鼠上唇，和时间花费的脸摩擦测量在3分钟块为45分钟。福尔马林引起了显着的双相（第一阶段：0-3分钟;第二阶段：15-33分钟）疼痛。海马内注射0.25、0.5 μ g剂量的组胺可减弱第二阶段，而1 μ g剂量的组胺可抑制两个阶段的疼痛。海马内注射美托洛尔和雷尼替丁在相同剂量的1，2和4 μ g时，单独使用没有产生任何影响。用相同剂量的4 μ g美托洛尔和雷尼替丁预处理可防止组胺（1 μ g）诱导的抗伤害感受。这些结果表明，在海马水平激活脑神经元组胺可能产生抗伤害感受。海马组胺的抗伤害作用可能是通过其H-1和H-2受体介导的。(C)2009爱思唯尔有限公司版权所有。
Brain neuronal histamine, through its receptors, is involved in central pain perception. In the present study, the effect of microinjection of histamine, mepyramine (a histamine H-1 receptor antagonist) and ranitidine (a histamine H-2 receptor antagonist) into the dorsal hippocampus was investigated on a model of orofacial pain in rats. Orofacial pain was induced by subcutaneous injection of formalin (1%, 50 mu l) in the upper lip in rats, and the time spent of face rubbing was measured in 3-min blocks for 45 min. Formalin induced a marked biphasic (first phase: 0-3 min; second phase: 15-33 min) pain. Intra-hippocampal injection of histamine at doses of 0.25, 0.5 mu g attenuated the second phase, and at a dose of 1 mu g, histamine suppressed both phases of pain. Intra-hippocampal injections of mepyramine and ranitidine at the same doses of 1, 2 and 4 mu g produced no effects when used alone. Pretreatments with mepyramine and ranitidine at a same dose of 4 mu g prevented histamine (1 mu g)-induced antinociception. These results indicate that the activation of brain neuronal histamine at the levels of the hippocampus may produce antinociception. Hippocampal histamine-induced antinociception may be mediated thorough its H-1 and H-2 receptors. (C) 2009 Elsevier B.V. All rights reserved.