ATP触发牛主动脉内皮细胞Ca^(2+)内流与Cl^-通道和PKC的关系

ATP-induced Ca^(2+) entry in bovine aortic endothelial cells and its relation with Cl - channels and PKC

目的 研究ATP触发牛主动脉内皮细胞Ca2 + 内流特性 ,Cl-通道阻断剂furosemide和PKC抑制剂staurosporine对其影响 ,阐明Cl-通道和PKC与ATP触发Ca2 + 内流的内在联系。方法 采用Fura 2荧光测定胞浆Ca2 + 变化技术 ,在培养的乳牛主动脉内皮细胞上观察药物对ATP触发Ca2 + 内流的影响。结果 ATP触发的Ca2 + 内流不受电压依赖性钙通道 (VDC)阻断剂nifedipine影响 ,但可被非VDC阻断剂SK&F 96 36 5 ,非选择性阻断Ca2 + 通道的金属离子NiSO4 和PKC抑制剂staurosporine抑制。furosemide (1 2 5～ 10 μmol·L-1)呈浓度依赖性抑制ATP触发的Ca2 + 内流 ,10 μmol·L-1可抑制 36 %± 14%。当staurosporine(10 0nmol·L-1)或SK&F 96 36 5 (15 μmol·L-1)分别对Ca2 + 内流最大程度抑制 34 %± 5 %和 6 4%± 11%后 ,furosemide可分别进一步抑制 7 6 %± 4%和 14%± 7%。结论 furosemide敏感的Ca2 + 内流与SK&F 96 36 5敏感的Ca2 + 内流存在非同一性。furosemide敏感的Cl-通道开放与PKC激活均参与了ATP触发的Ca2 + 内流 ,这两种因素与Ca2 + 内流之间存在内在联系。

AIM To investigate effects of Cl - channel blocker furosemide and protein kinase C (PKC) inhibitor staurosporine on ATP induced Ca 2+ entry in bovine aortic endothelial cells (BAEC) METHODS The effects of drugs on intracellular calcium concentration ([Ca 2+ ] i) were investigated with Fura 2 fluorescence technique RESULTS The [Ca 2+ ] i increase response to ATP was biphasic, atransient [Ca 2+ ] i peak followed by a sustained [Ca 2+ ] i plateau ATP induced Ca 2+ entry was significantly reduced by voltage independent Ca 2+ channel blocker SK&F 96365, PKC inhibitor staurosporine and the inorganic Ca 2+ channel blocker NiSO 4, but not by nifedipine, a voltage dependent Ca 2+ channel blocker ATP induced Ca 2+ entry was inhibited in concentration dependent manner by Cl - channel blocker furosemide (from 1 25 to 10 μmol·L -1 ) When SK&F 96365 or staurosporine produced the maximal effects, the subsequent addition of furosemide further decreased the [Ca 2+ ] i by 7 6%±4% and 34%±5% CONCLUSION Furosemide sensitive Cl - channel is related to ATP induced Ca 2+ entry The Ca 2+ influx sensitive to furosemide is not identical to SK&F 96365 Opening of furosemide sensitive Cl - channel accompanied by ATP induced [Ca 2+ ] i elevation in BAEC is related to PKC