Ice K S, Hay D W, Fleming W W, Robinson R L, Fedan J S
J Pharmacol Exp Ther. 1985 Nov;235(2):349-53.
Postjunctional supersensitivity of the smooth muscle of the guinea-pig vas deferens induced by denervation, decentralization and treatment of animals with reserpine has been attributed, in part, to a partial membrane depolarization (8-10 mV) resulting from reduced electrogenic Na+,K+-pumping activity. This study was undertaken to characterize sensitivity changes which occur after treatment of animals with 6-hydroxydopamine (100 mg/kg + 250 mg/kg i.v., 1 day apart). Seven days after the second injection, concentration-response curves for isometric contractile responses to norepinephrine, methoxamine, acetylcholine and histamine were shifted 40.6-, 1.7-, 3.6- and 2.7-fold, respectively, to the left of control; however, the sensitivity to KCl was not increased, which contrasts with the results after denervation, decentralization and reserpine treatment. Ouabain (10(-5) M) produced 1.8- and 1.3-fold leftward shifts of the KCl concentration-response curves in tissues from control and 6-hydroxydopamine-treated animals, respectively. The pronounced effect of ouabain in tissues from treated animals may be an indication that 6-hydroxydopamine treatment does not result in as much inhibition of electrogenic Na+,K+-pumping, and resultant membrane depolarization, as other methods which induce supersensitivity of the guinea-pig vas deferens.
去神经、去除神经节以及用利血平处理动物所诱导的豚鼠输精管平滑肌的接头后超敏反应，部分归因于由于生电钠钾泵活性降低导致的部分膜去极化（8 - 10 mV）。本研究旨在表征用6 - 羟基多巴胺（100 mg/kg + 250 mg/kg静脉注射，间隔1天）处理动物后发生的敏感性变化。第二次注射后7天，去甲肾上腺素、甲氧明、乙酰胆碱和组胺等长收缩反应的浓度 - 反应曲线分别向左移动了40.6倍、1.7倍、3.6倍和2.7倍；然而，对氯化钾的敏感性并未增加，这与去神经、去除神经节和利血平处理后的结果形成对比。哇巴因（10⁻⁵ M）分别使对照动物和6 - 羟基多巴胺处理动物组织中的氯化钾浓度 - 反应曲线向左移动了1.8倍和1.3倍。哇巴因对处理动物组织的显著作用可能表明，与其他诱导豚鼠输精管超敏反应的方法相比，6 - 羟基多巴胺处理对生电钠钾泵的抑制以及由此导致的膜去极化程度较小。
