Den Hertog A, Van den Akker J
Eur J Pharmacol. 1987 Jun 26;138(3):367-74. doi: 10.1016/0014-2999(87)90475-4.
Changes in the potential and contractility of smooth muscle cells of guinea-pig taenia caeci were measured (22 degrees C) in order to investigate the effect of mebeverine, a derivative of beta-phenylethylamine, on alpha 1-receptor-operated ion channels in particular. Mebeverine (6 X 10(-6) M) showed atropine-like properties by shifting to the right the concentration-response curve obtained with carbachol. Hyperpolarization and cessation of spike activity of the muscle cells, accompanied by an increased amplitude of the electrotonic potential were observed in the presence of mebeverine (6 X 10(-5] after block of the alpha 2-, beta- and muscarinic receptors. This effect of mebeverine was not observed in low-sodium solution (23.8 mM), suggesting that mebeverine decreased sodium permeability. The alpha 1-receptor-induced hyperpolarization caused by adrenaline (3 X 10(-6) M) in the presence of mebeverine declined after reaching an initial maximum. The hyperpolarization induced by a second addition of adrenaline to the preparation was decreased and sustained in the presence of mebeverine, while the decrease of the electrotonic potential evoked during the alpha 1 response was less pronounced. The transient hyperpolarization representing the alpha 1 response in the absence of extracellular calcium developed more slowly in the presence of mebeverine, the area of the response being constant. When the experiment was continued in calcium-free solution after a short exposure to calcium-containing Krebs solution still in the presence of mebeverine, the alpha 1-receptor-induced hyperpolarization was suppressed.(ABSTRACT TRUNCATED AT 250 WORDS)
为了特别研究β-苯乙胺衍生物美贝维林对α1受体操纵的离子通道的影响，在22℃下测量了豚鼠盲肠带平滑肌细胞的电位和收缩性变化。美贝维林（6×10⁻⁶M）通过使卡巴胆碱获得的浓度-反应曲线右移而表现出阿托品样特性。在阻断α2、β和毒蕈碱受体后，在存在美贝维林（6×10⁻⁵）的情况下，观察到肌肉细胞超极化和动作电位停止，同时电紧张电位幅度增加。在低钠溶液（23.8 mM）中未观察到美贝维林的这种作用，表明美贝维林降低了钠通透性。在美贝维林存在下，肾上腺素（3×10⁻⁶M）诱导的α1受体超极化在达到初始最大值后下降。在美贝维林存在下，第二次向制剂中添加肾上腺素诱导的超极化减少并持续，而α1反应期间诱发的电紧张电位的降低不太明显。在没有细胞外钙的情况下代表α1反应的短暂超极化在美贝维林存在下发展得更慢，反应面积恒定。当在仍然存在美贝维林的情况下短暂暴露于含 Krebs 溶液的钙后，在无钙溶液中继续实验时，α1受体诱导的超极化被抑制。（摘要截断于250字）
