【摘要】 目的观察血小板激活因子（PAF）是否影响心室肌细胞钙离子浓度([Ca²⁺]i)以及通过哪条信号转导通路起作用。方法采用酶法分离豚鼠心室肌细胞,用PAF刺激细胞;用Fluo-3/AM和共聚焦显微镜观察细胞[Ca²⁺]i;用2-氨乙基硼酸二苯酯（2-APB）和雷诺定（ryanodine）分别阻断IP3和雷诺定信号通路。全细胞膜片钳技术观察心室肌细胞L型钙电流（ICa-L）。结果无论在有钙还是无钙台氏液,PAF（1pmol·L-1¹0nmol·L-1）都能增加心肌细胞[Ca²⁺]i,其作用能够被2-APB2μmo·lL-1阻断,而不能被雷诺定200μmol·L-1阻断。PAF1nmol·L-1对ICa-L没有明显影响,对照组和实验组电流密度分别为-（11.0±1.9）和-（10.5±1.3）pA·pF-1。结论PAF能增加豚鼠心室肌细胞[Ca²⁺]i,IP3信号通路可能参与了这一过程。更多还原

【Abstract】 AIM To observe whether platelet activating factor （PAF） will influence cytosolic calcium concentration （[Ca 2+ ]_i） in ventricular myocytes and which signaling pathway is involoved.METHODS Ventricular myocytes were isolated enzymatically. Cells were stimulated with PAF, and [Ca 2+ ]_i was measured with calcium indicator Fluo-3/AM and a confocal laser microscope. For the observation of signaling channel mediated by inositol 1,4,5-trisphosphate （IP₃） and ryanodine, 2-aminoethyl diphenylborate （2-APB, 2 μmol·L -1 ） and ryanodine （200 μmol·L -1 ） were used respectively for blocking the signaling channel. Whole-cell patch clamp was used to study the effect of PAF on L-type calcium channel （I Ca-L ）.RESULTS PAF （1 pmol·L -1 -10 nmol·L -1 ） increased [Ca 2+ ]_i in Tyrode′s solution with or without calcium, and the effect was inhibited by 2-APB, but not by ryanodine. I Ca-L was not changed by PAF 1 nmol·L -1 〔-（11.0±1.9） vs -（10.5±1.3） pA·pF -1 〕.CONCLUSION Increasing [Ca 2+ ]_i of cardiomyocytes induced by PAF is associated with IP₃ pathway, but has nothing to do with I Ca-L and ryanodine pathway.更多还原