Detection of a P-glycoprotein related pump in Chironomus larvae and its inhibition by verapamil and cyclosporin A
Detection of a P-glycoprotein related pump in Chironomus larvae and its inhibition by verapamil and cyclosporin A
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DOI：
10.1016/s0305-0491(98)10137-2
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发表时间：
1998-12-01
影响因子：
2.2
通讯作者：
Vilcinskas, A
中科院分区：
文献类型：
--
作者：
Podsiadlowski, L;Matha, V;Vilcinskas, A
在河滨Chironomus riparius幼虫的肛门乳头中检测到一种功能类似于哺乳动物p -糖蛋白的膜相关atp依赖性外排泵。利用p -糖蛋白单克隆抗体对幼虫组织进行免疫组化分析，并辅以体内和体外功能试验，证实了外源物质运输机制的存在。在典型p糖蛋白底物（长春碱、放线菌素D或伊维菌素）存在的情况下，匀浆组分的体外atp酶活性增加。这种增加不受其他膜atp酶抑制剂（叠氮化钠，EGTA，瓦巴因）的影响。但对钒酸盐、环孢素A和维拉帕米敏感，这些物质抑制哺乳动物p糖蛋白介导的atp消耗。特异性p -糖蛋白抑制剂如维拉帕米或环孢素A的亚致死浓度协同提高了河岸嗜血杆菌对伊维菌素的死亡率。虽然环孢素A起源于昆虫病原真菌，但其在昆虫中的作用方式及其在感染过程中的作用尚不清楚。我们的结果在一定程度上支持了一种假设，即这种化合物可能被释放，以促进被感染宿主被通常由p糖蛋白相关泵去除的异种生物中毒。讨论了昆虫p -糖蛋白同源物在多种杀虫剂抗性竞争中的可能作用。(C) 1998爱思唯尔科学公司版权所有。
A membrane associated ATP-dependent efflux pump, similar in function to mammalian P-glycoprotein, was detected in anal papillae of Chironomus riparius larvae. Immunohistochemical analysis of larval tissues, using monoclonal antibodies against P-glycoprotein, was supplemented by functional in vivo and in vitro assays which confirmed the existence of a mechanism for transporting xenobiotic substances. The in vitro ATPase activity of homogenate fractions increased in the presence of typical P-glycoprotein substrates (vinblastine, actinomycin D or ivermectin). This increase was unaffected by inhibitors of other membrane ATPases (sodium azide, EGTA, ouabain). but sensitive to vanadate, cyclosporin A and verapamil which inhibit mammalian P-glycoprotein mediated ATP-consumption. Sublethal concentrations of specific P-glycoprotein-inhibitors such as verapamil or cyclosporin A synergistically enhanced the mortality of C. riparius towards ivermectin. Although cyclosporin A originates from entomopathogenic fungi, its mode of action in insects and its function during infection are not understood. Our results lend some credit to the hypothesis that this compound is possibly released to promote poisoning of the infected host by xenobiotics which are normally removed by a P-glycoprotein related pump. The putative role of insect P-glycoprotein homologues in the contest of multiple resistance towards insecticides is discussed. (C) 1998 Elsevier Science inc. All rights reserved.