Kakuta Y, Okayama H, Aikawa T, Kanno T, Ohyama T, Sasaki H, Kato T, Takishima T
First Department of Internal Medicine, Tohoku University School of Medicine, Sendai, Japan.
J Allergy Clin Immunol. 1988 Feb;81(2):460-8. doi: 10.1016/0091-6749(88)90918-9.
The activation of macrophages has been reported to be associated with Ca-activated K permeability change. In order to study this permeability change in human alveolar macrophages, we examined alveolar macrophages electrophysiologically at a single channel level. We observed two types of Ca-activated K channel currents having conductances of 218 +/- 2 and 32 +/- 0.6 picosiemens in symmetrical 154 mmol/L KCl solutions. The characteristics, such as voltage dependency and Ca sensitivity, as well as channel conductance, were different between these two types of channel currents. Quinine (a blocker of Ca-activated K conductance), 0.5 mmol/L, reduced these channel currents by 45 +/- 8% and 31 +/- 8%. Quinine, 0.5 mmol/L, also inhibited chemiluminescence and leukotriene B4 release by 82 +/- 6 to 88 +/- 3% and 88 +/- 2%, respectively. These results suggest the presence of two types of Ca-activated K channels, which may be related to the release of inflammatory mediators from human alveolar macrophages.
据报道，巨噬细胞的激活与钙激活钾通透性变化有关。为了研究人类肺泡巨噬细胞的这种通透性变化，我们在单通道水平上对肺泡巨噬细胞进行了电生理检查。在对称的154 mmol/L氯化钾溶液中，我们观察到两种钙激活钾通道电流，其电导分别为218±2和32±0.6皮西门子。这两种通道电流在电压依赖性、钙敏感性以及通道电导等特性方面存在差异。0.5 mmol/L的奎宁（一种钙激活钾电导阻滞剂）使这些通道电流分别降低了45±8%和31±8%。0.5 mmol/L的奎宁还分别抑制了化学发光和白三烯B4的释放，抑制率分别为82±6%至88±3%和88±2%。这些结果表明存在两种钙激活钾通道，它们可能与人类肺泡巨噬细胞释放炎症介质有关。
