Braga P C, Soldavini E, Pecile A, Sibilia V, Netti C
Department of Pharmacology, School of Medicine, University of Milan, Italy.
Experientia. 1996 Jan 16;52(1):60-5. doi: 10.1007/BF01922417.
Intracerebroventricular (i.c.v.) administration of histamine (HA, 0.025-0.1 microM/rat) to arthritic rats induces a dose-related inhibition of the neuronal thalamic firing evoked by peripheral noxious stimuli. To characterize the type(s) of HA receptors involved in this depressing activity of the amine we used electrophysiological techniques to examine the effects of i.c.v. administration of H1 and H2 agonists and antagonists on the spontaneous and evoked nociceptive firing of the thalamic neurons in rats rendered arthritic by Freund's adjuvant. The H1 agonist 2-pyridylethylamine (0.4-1.0 microM/rat, i.c.v.) displayed a dose-dependent antinociceptive effect very similar to that of HA, while the H2 agonist dimaprit (0.05-0.2 microM/rat, i.c.v.) did not modify thalamic firing. Neither mepyramine (H1 antagonist, 0.1 microM/rat, i.c.v.) nor zolantidine (H2 antagonist, 0.01 microM/rat, i.c.v.) modified the evoked firing of rat thalamic neurons. When administered before HA (0.1 microM/rat, i.c.v.) mepyramine but not zolantidine was able to inhibit the antinociceptive effect of HA. On the basis of the present electrophysiological results, we suggest that a specific interaction of histamine with H1 receptors may be important for its antinociceptive effect on afferent peripheral inputs to the thalamus.
向患有关节炎的大鼠脑室内（i.c.v.）注射组胺（HA，0.025 - 0.1微摩尔/大鼠）可诱导剂量相关的对由外周伤害性刺激诱发的丘脑神经元放电的抑制作用。为了确定参与该胺类这种抑制活性的HA受体类型，我们使用电生理技术来检查i.c.v.注射H1和H2激动剂及拮抗剂对弗氏佐剂诱导的关节炎大鼠丘脑神经元自发和诱发的伤害性放电的影响。H1激动剂2 - 吡啶乙胺（0.4 - 1.0微摩尔/大鼠，i.c.v.）表现出与HA非常相似的剂量依赖性抗伤害感受作用，而H2激动剂二甲双胍（0.05 - 0.2微摩尔/大鼠，i.c.v.）并未改变丘脑放电。H1拮抗剂美吡拉敏（0.1微摩尔/大鼠，i.c.v.）和H2拮抗剂佐兰替丁（0.01微摩尔/大鼠，i.c.v.）均未改变大鼠丘脑神经元的诱发放电。当在HA（0.1微摩尔/大鼠，i.c.v.）之前给药时，美吡拉敏而非佐兰替丁能够抑制HA的抗伤害感受作用。基于目前的电生理结果，我们认为组胺与H1受体的特异性相互作用可能对其对丘脑传入外周输入的抗伤害感受作用很重要。
