左卡尼汀对波动性高糖处理大鼠心肌细胞脂联素受体表达影响的实验研究

Effects of L-carnitine on the adiponectin receptors expression of RMCs induced by intermittent high glucose

目的探讨左卡尼汀（L-carnitine,L-CN）对波动性高糖处理大鼠心肌细胞（rat myocardial cell,RMC）脂联素受体（AdipoR1和AdipoR2）表达的影响。方法将RMC在高糖（20 mmol/L）、波动性高糖培养液（5.5 mmol/L和20 mmol/L每隔8 h轮换1次）中培养5 d后,随机分为正常组、高糖组、波动性高糖组、波动性高糖＋L-CN处理组（102、2.5×102、5×102、103、104、105及106μΜ）。运用细胞增殖试验（CCK8法）检测细胞存活率,依据细胞增殖试验的结果,将分组调整为阴性对照（正常组）、阳性对照（波动性高糖组）、波动性高糖组＋L-CN处理组（102、2.5×102、5×102、103及104μΜ）,应用实时荧光定量PCR方法检测AdipoR mRNA表达的改变。结果与正常组相比,高糖组心肌细胞OD值降低不明显;波动性高糖组心肌细胞OD值减小,与正常组比较差异有显著性（P〈0.05）。提示波动性高糖组对细胞的损害作用明显高于单纯高糖组。L-CN（5×102μΜ）处理组较波动性高糖组OD值增加,差异有显著性（P〈0.05）;L-CN（2.5×102、103及104μΜ）处理组较波动性高糖组OD值增加,差异无显著性（P〉0.05）;L-CN（105μΜ和106μΜ）处理组较波动性高糖组OD值下降,提示左卡尼汀的作用浓度在102~104μΜ之间。L-CN处理后RMCs AdipoR1 mRNA、AdipoR2mRNA均明显增高（P〈0.01）,当L-CN工作浓度在5×102μΜ时,AdipoR表达增加更明显。结论波动性高糖与单纯高糖相比对细胞的损害作用更强,左卡尼汀可在一定程度上降低波动性高糖引起的细胞损害作用,且药物有效浓度在102~104μΜ之间。在波动性高糖环境中,RMC AdipoR mRNA表达下调（P〈0.01）,左卡尼汀能明显上调波动性高糖处理后大鼠心肌细胞AdipoR mRNA表达（P〈0.01）,从而为L-CN类药物更广泛应用于糖尿病心肌病变提供了新思路和新证据。

【Objective】To investigate the effect of L-carnitine（L-CN） on the AdipoR1 and AdipoR2 expression of RMCs induced by intermittent high glucose.【Methods】After exposed to intermittent high glucose for 5 d,RMCs were incubated with L-CN（102,2.5×102,5×102,103,104 μΜ） for 24 hours.Use CCK8 method to detect cell survival application.The AdipoR1 and AdipoR2 mRNA expression levels in RMCs were also determined by rea1-time PCR.【Results】The intermittent high glucose OD value decreased compared with the normal group was significant difference（P 0.05）;L-CN（102,2.5×102 μΜ） treatment group compared with the intermittent high glucose group OD values increased,but no statistically significant.L-CN（5×102,103,104 μΜ） treatment group compared fluctuations in OD values increased（P 0.05）;L-CN can promoting cell proliferation.L-CN treated RMC AdipoR1 mRNA,AdipoR2 mRNA were significantly higher（P 0.01）,and the concentration increased to 5×102 μΜ,AdipoR mRNA expression was markedly enhanced.【Conclusions】The intermittent high glucose can inhibit metabolism in RMCs,decrease cell survival but L-CN promoting cell proliferation.L-CN can inhibit significantly the downregulation of AdipoR in RMCs induced by intermittent high glucose in a dose-dependent manner.