Wallis D I, Dun N J
Department of Pharmacology, Loyola University, Stritch School of Medicine, Maywood, IL 60153.
J Auton Nerv Syst. 1987 Dec;21(2-3):185-94. doi: 10.1016/0165-1838(87)90021-x.
Responses to 5-hydroxytryptamine (5-HT) applied by pressure ejection to guinea-pig coeliac ganglion cells were recorded intracellularly in vitro. Three types of responses were observed: a fast depolarization (43% of cells), a slow depolarization (25%) and a biphasic response comprising an initial fast followed by a slow depolarization (30%). Fast depolarizations had a mean duration of 6.4 s and were associated with a decrease in membrane input resistance. On hyperpolarizing the membrane, responses increased in amplitude; the mean reversal potential was -23 mV. Fast responses were nearly eliminated in a Na-free medium but were unaffected by low Ca/high Mg solution or by low Cl medium. Fast responses were depressed by MDL 72222, quipazine, metoclopramide, and by relatively high concentrations of D-tubocurarine, but unaffected by methysergide. Slow responses had a mean duration of 62 s and were associated either with no change or a slight fall in membrane resistance. hyperpolarizing the membrane, slow responses were increased in most but not all cells tested. Slow depolarizations were depressed by methysergide but unaffected by agents that suppressed the fast responses. The biphasic response displayed electrophysiological and pharmacological characteristics of both the fast and slow depolarizations. It is concluded that guinea-pig coeliac ganglion cells display either a rapid depolarization, a slow depolarization or a biphasic response to 5-HT, that the fast depolarization appears to be mediated by a conductance increase to Na and K, while a different mechanism appears to underlie the slow depolarization, and that the two responses are mediated by different kinds of 5-HT receptor.
在体外对豚鼠腹腔神经节细胞进行细胞内记录，观察压力喷射施加5-羟色胺（5-HT）后的反应。观察到三种类型的反应：快速去极化（43%的细胞）、缓慢去极化（25%）和双相反应，包括初始快速去极化后接着缓慢去极化（30%）。快速去极化的平均持续时间为6.4秒，且与膜输入电阻降低有关。使膜超极化时，反应幅度增加；平均反转电位为-23 mV。在无钠培养基中，快速反应几乎消失，但不受低钙/高镁溶液或低氯培养基的影响。快速反应受到MDL 72222、喹哌嗪、甲氧氯普胺以及相对高浓度的筒箭毒碱抑制，但不受麦角新碱影响。缓慢反应的平均持续时间为62秒，且与膜电阻无变化或略有下降有关。使膜超极化时，在大多数但并非所有测试细胞中缓慢反应增强。缓慢去极化受到麦角新碱抑制，但不受抑制快速反应的药物影响。双相反应表现出快速和缓慢去极化的电生理和药理学特征。结论是，豚鼠腹腔神经节细胞对5-HT表现出快速去极化、缓慢去极化或双相反应，快速去极化似乎由对钠和钾的电导增加介导，而缓慢去极化似乎由不同机制介导，且这两种反应由不同类型的5-HT受体介导。
