异丙酚对兔离体气管平滑肌细胞内游离钙离子浓度的影响

Effect of propofol on intracellular calcimn ion concentration in isolated rabbit tracheal smooth muscle cells

目的评价异丙酚对兔离体气管平滑肌细胞内游离钙离子浓度（[Ca2＋]i）的影响。方法采用急性酶分离方法分离兔气管平滑肌细胞，采用随机数字表法，将细胞随机分为3组（n=5）：异丙酚组（I组，终浓度300pmol／L）、异丙酚（终浓度300μmol／L）＋2-氨乙基硼酸二苯酯（终浓度40μmol／L）（1I组）和异丙酚（300μmaol／L）＋斯里兰卡肉桂碱（终浓度10μmol／L）（Ⅲ组）。I组加入终浓度300μmol／L的异丙酚，孵育15min后，用无钙的Hank平衡盐溶液冲洗3次，加入1μmol／L乙酰胆碱，记录[Ca2＋]i。II组加入终浓度40μmol／L的2。氨乙基硼酸二苯酯孵育15min后，再加入终浓度为300μmol／L的异丙酚，与2．氨乙基硼酸二苯酯共同孵育15min后，用无钙的Hank平衡盐溶液冲洗3次，加入1μmol／L的乙酰胆碱。Ⅲ组加入终浓度10μmol／L的斯里兰卡肉桂碱孵育15min后，再加入终浓度为300μmol／L的异丙酚，与斯里兰卡肉桂碱共同孵育15min后，用无钙的Hank平衡盐溶液冲洗3次，再加入1μmol／L的乙酰胆碱。通过负荷钙离子荧光指示剂Fluo-3／AM测定气管平滑肌细胞内[Ca2＋]i。结果与I组比较，Ⅱ组气管平滑肌细胞内[Ca2＋]i差异无统计学意义（P〉0．05），III组[Ca2＋]i明显降低（P〈0．05）。结论异丙酚可降低兔离体气管平滑肌细胞内[Ca2＋]i，其机制可能与抑制内质网1，4，5-三磷酸肌醇通路有关，而与内质网兰诺定通路无关。

Objective To investigate the effect of propofol on the intracellular calcium ion concentration （[ Ca2＋] i） in isolated rabbit tracheal smooth muscle cells （TSMCs）. Methods The single rabbit TSMC was isolated by acute enzymatic isolation method as described by Cheng et al. The isolated TSMCs were randomly divided into 3 groups （ n =5 each） ： propofol group （group II ）, propofol ＋ 2-aminoethoxy-diphenylborate （2-APB） group （group II ） and propofol ＋ the blocker ryanodine group （group III ）. In group I , the cells were incubated with propofol with the final concentration of 300 μmol/L for 15 mln, followed by washing with calcium-free Hank＇s balanced salt solution （HBSS） for 3 times, acetylcholine 1μmol/L was then added to the culture medium and [Ca2＋ ] i was recorded. In group II , the cells were incubated with 2-APB with the final concentration of 40 μmol/L for 15 min, propofol with the final concentration of 300μmol/L was then added, the ceils were incubated with 2-APB and propofol for another 15 min, followed by washing with calcium-free HBSS for 3 times, and acetylcholine 1 μmol/L was then added. In group III, the cells were incubated with ryanodine with the final concentration of 10 μmol/L for 15 min, propofol with the final concentration of 300 μmol/L was then added, the cells were incubated with ryanodine and propofol for another 15 min, followed by washing with calcium-free HBSS for 3 times, and acetylcholine 1 μmol/L was then added. [ Ca2＋] i in TSMCs was measured using the fluorescent C2 ＋ indicator fluor-3/AM. Results Compared with group I, no significant change＇was found in [Ca2＋ ]i.in group II （P 〉 0.05）, while [ Ca2 ＋ ] i Was significantly decreased in group III （ P 〈 0.05）. Conclusion Propofol can decrease the [ Ca2＋ ] i in isolated rabbit TSMCs, and the mechanism may be related to inhibition of inositol 1,4,5-trisphosphate pathway, but not ryanodine pathway.