Ochi Sadayuki, Oda Masataka, Nagahama Masahiro, Sakurai Jun
Department of Microbiology, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan.
Biochim Biophys Acta. 2003 Jun 27;1613(1-2):79-86. doi: 10.1016/s0005-2736(03)00140-8.
Clostridium perfringens alpha-toxin is able to lyse various erythrocytes. Exposure of horse erythrocytes to alpha-toxin simultaneously induced hot-cold hemolysis and stimulated production of diacylglycerol and phosphorylcholine. When A23187-treated erythrocytes were treated with the toxin, these events were dependent on the concentration of extracellular Ca2+ . Incubation with the toxin of BAPTA-AM-treated horse erythrocytes caused no hemolysis or production of phosphorylcholine, but that of the BAPTA-treated erythrocytes did. When Quin 2-AM-treated erythrocytes were incubated with the toxin in the presence of 45Ca2+, the cells accumulated 45Ca2+ in a dose- and a time-dependent manner. These results suggest that the toxin-induced hemolysis and hydrolysis of phosphatidylcholine are closely related to the presence of Ca2+ in the cells. Flunarizine, a T-type Ca2+ channel blocker, and tetrandrine, an L- and T-type Ca2+ channel blocker, inhibited the toxin-induced hemolysis and Ca2+ uptake. However, L-type Ca2+ channel blockers, nifedipine, verpamil and diltiazem, an N-type blocker, omega-conotoxin SVIB, P-type blockers, omega-agatoxin TK and omega-agatoxin IVA, and a Q-type blocker, omega-conotoxin MVII C, had no such inhibitory effect. The observation suggests that Ca2+ taken up through T-type Ca2+ channels activated by the toxin plays an important role in hemolysis induced by the toxin.
产气荚膜梭菌α毒素能够溶解多种红细胞。马红细胞暴露于α毒素会同时诱导热冷溶血，并刺激二酰基甘油和磷酸胆碱的产生。当用A23187处理过的红细胞再用该毒素处理时，这些事件依赖于细胞外Ca2+的浓度。用BAPTA - AM处理过的马红细胞与毒素一起孵育不会导致溶血或磷酸胆碱的产生，但用BAPTA处理过的红细胞则会。当用Quin 2 - AM处理过的红细胞在45Ca2+存在的情况下与毒素一起孵育时，细胞会以剂量和时间依赖的方式积累45Ca2+。这些结果表明，毒素诱导的溶血和磷脂酰胆碱的水解与细胞内Ca2+的存在密切相关。氟桂利嗪，一种T型Ca2+通道阻滞剂，以及粉防己碱，一种L型和T型Ca2+通道阻滞剂，可抑制毒素诱导的溶血和Ca2+摄取。然而，L型Ca2+通道阻滞剂硝苯地平、维拉帕米和地尔硫䓬，N型阻滞剂ω -芋螺毒素SVIB，P型阻滞剂ω -阿加毒素TK和ω -阿加毒素IVA，以及Q型阻滞剂ω -芋螺毒素MVII C，均无此类抑制作用。该观察结果表明，通过毒素激活的T型Ca2+通道摄取的Ca2+在毒素诱导的溶血中起重要作用。
