Todorov S
Institute of Physiology, Bulgarian Academy of Sciences, Sofia.
Methods Find Exp Clin Pharmacol. 1990 Dec;12(10):685-9.
The interaction of histamine and other histaminergic agents with adrenergic neurotransmission in blood vessels was studied in vitro. The experiments were carried out on ear central arteries isolated from male Chinchilla rabbits. The proximal segment of the artery was perfused with Krebs-Henseleit solution at a rate of 3.0 ml/min and was allowed a 120-min adaptation before the experiments. Contractions of the arterial smooth muscle were evoked either by noradrenaline (NA) or by low-frequency electrical stimulation (LFES). The effects of histamine and the other histaminergic agents on the arterial tone and on the NA- or LFES-induced contractions were studied. When applied extralumenally in concentrations higher than 1 x 10(-12) M histamine and 2-(2-aminoethyl) thiazole (2-AET) enhanced the LFES-induced smooth-muscle contractions. Dimaprit (DMP) did not markedly change the LFES-contractile effects. Diphenhydramine (DPH) and mepyramine (MEP) in higher concentrations potentiated the contractions in response to LFES. Ranitidine (RAN) moderately potentiated and cimetidine (CIM) did not affect the LFES-evoked contractions of the artery. None of the drugs tested significantly changed the NA-induced contractions. The results only partly confirm the assumption that histamine exerts its modulatory effects on adrenergic neurotransmission via postsynaptic excitatory H1-receptors and presynaptic inhibitory H2-receptors.
在体外研究了组胺及其他组胺能药物与血管中肾上腺素能神经传递的相互作用。实验采用从雄性青紫蓝兔分离的耳中央动脉进行。动脉近端段以3.0 ml/min的速率用克雷布斯 - 亨泽莱特溶液灌注，实验前给予120分钟的适应时间。动脉平滑肌收缩可由去甲肾上腺素（NA）或低频电刺激（LFES）诱发。研究了组胺及其他组胺能药物对动脉张力以及对NA或LFES诱发收缩的影响。当以高于1×10⁻¹² M的浓度经腔外应用时，组胺和2 -（2 - 氨基乙基）噻唑（2 - AET）增强了LFES诱发的平滑肌收缩。甲双咪脲（DMP）未明显改变LFES的收缩效应。较高浓度的苯海拉明（DPH）和美吡拉敏（MEP）增强了对LFES的收缩反应。雷尼替丁（RAN）适度增强，而西咪替丁（CIM）不影响动脉LFES诱发的收缩。所测试的药物均未显著改变NA诱发的收缩。这些结果仅部分证实了组胺通过突触后兴奋性H1受体和突触前抑制性H2受体对肾上腺素能神经传递发挥调节作用的假设。
