Kitayama S, Ohtsuki H, Morita K, Dohi T, Tsujimoto A
Department of Pharmacology, Hiroshima University School of Dentistry, Japan.
Neurosci Lett. 1990 Aug 24;116(3):275-9. doi: 10.1016/0304-3940(90)90086-o.
Changes of plasma membrane potential of isolated bovine adrenal chromaffin cells were monitored by fluorescent probe, bis-[1,3-diethyl-thiobarbiturate]trimethineoxonol (bis-oxonol), which responds to depolarization, resulting in increase of its fluorescence. Excess K+, gramicidin D, veratridine and ouabain all increased bis-oxonol fluorescence. Cells challenged with acetylcholine (ACh) or gamma-aminobutyric acid (GABA) produced a steady-state increase of bis-oxonol fluorescence, reflecting that averaged depolarization occurred continuously. Both effects were dependent on concentration with similar range, and mediated via nicotinic ACh receptor and GABAA receptor, respectively. Application of GABA with ACh or veratridine not only simultaneously but also pretreatedly caused an additive increment of bis-oxonol fluorescence. These results suggest that chromaffin cells in vitro reveal an additively enhanced change of plasma membrane potential in response to the combination of depolarizing stimuli.
通过荧光探针双-[1,3-二乙基硫代巴比妥酸盐]三甲川草酚菁（双草酚菁）监测分离的牛肾上腺嗜铬细胞的质膜电位变化，该探针响应去极化，导致其荧光增加。过量的钾离子、短杆菌肽D、藜芦碱和哇巴因均增加双草酚菁荧光。用乙酰胆碱（ACh）或γ-氨基丁酸（GABA）刺激细胞会使双草酚菁荧光产生稳态增加，这反映出平均去极化持续发生。这两种效应都依赖于浓度且范围相似，分别通过烟碱型ACh受体和GABAA受体介导。将GABA与ACh或藜芦碱同时应用以及预先应用均会使双草酚菁荧光产生累加性增加。这些结果表明，体外培养的嗜铬细胞在对去极化刺激组合的反应中显示出质膜电位的累加性增强变化。
