蝙蝠葛苏林碱对PC12细胞内游离钙浓度的影响

目的进一步探讨蝙蝠葛苏林碱（Dau）的抗脑缺血／缺氧损伤与其钙拮抗作用间的关系。方法：培养的PC12细胞用Fura－2／AM负载，用AR－CM－MIC阳离子测定系统观测Dau对单细胞内游离钙（[Ca(2+)]_i）升高的影响。结果：Dau（0．1～100μmol·L(－1)）可浓度依赖性抑制高钾和caffeine引起的[Ca(2+)］_i增加，对肌浆网钙泵抑制剂cy－clopiszonicacid引起的[Ca(2+)]_i升高也有抑制作用。结论：Dau不仅抑制电压依赖性钙通道开放引起的细胞外钙内流和caffeine引起的内钙释放．而且对钙泵也可能有影响，这可能是其抗脑缺血／缺氧损伤的重要机制。

Effects of daurisoline on cytosolic free calcium in attached PC12 cells

To explore the relationshipsbetween calcium antagonism and cerebral anti-is-chemic effect of daurisoline (Dau ). METHODS:Attached PC12 cells were loaded with the calci-um fluorescent indicator Fura-2/AM. the measurements of cytosolic free Ca2 in single cellswere carried out using AR-CM--MIC system'The effects of Dan on the increase in cytosolicfree Ca2 were investigated. RESULTS: Dan(0. 1-100 pmol. L(-1 ) was found to inhibit highK and caffeine-induced [Ca2 ], elevation in thedose-dependent manner, the values of ICS, were18. 2 and 5. 41 Umol. L(-1), respectively. Moreover, Dan was also shown to inhibit the Ca2 ATPase inhibitor cyclopiazonic acid (CPA )stimulated [Ca2 ], elevation. This effect wasmore potent in the presence of extracellular Ca2 (IC50 = 29. 3 umol. L -1 ) than in its absence(IC50 = 44. 6 umol. L-1 ). CONCLUSION: 'l-heresults suggest that Dan inhibits not only volt-age-dependent calcium channel but also Ca2 release from intracellular stores, and may havesome effects on Ca2 -ATPase. This may be tileimportant mechanism of action for its antiucerebral ischemic effect.