同型半胱氨酸诱导心肌细胞增殖并增加细胞内游离钙浓度

Homocysteine induces cardiomyocyte hypertrophy and increases intracellular free calcium concentration

目的 探讨高同型半胱氨酸(Hey)血症对心肌细胞的作用。方法 采用差速贴壁法培养SD乳鼠心肌细胞,与Hcy在体外共同培养,用[3H]-胸腺嘧啶核苷([3H]-TdR)掺入法测定心肌细胞DNA合成;用Lowry法检测心肌细胞蛋白质含量。Hcy对心肌细胞内游离钙离子浓度([Ca2+]i)的影响采用Fura-2/AM荧光染色法。结果 Hcy以剂量和时间依赖的方式使培养的SD乳鼠心肌细胞[3H]-TdR掺入率和单个心肌细胞蛋白质含量明显增加;Hcy并以剂量依赖方式增加心肌细胞[Ca2+]i。结论 Hcy能刺激心肌细胞增殖并增加心肌细胞[Ca2+]i,提示高同型半胱氨酸血症可能参与了慢性肾功能衰竭患者心肌肥厚的发生。

Objective To observe the effect of homocysteine (Hey) on growth of cardiomyocyte and the concentration of intracellular free calcium( [Ca2+ ]i)of cultured cardiac myocyte. Methods Primary myocardial cells from Sprague-Dawley neonatal rats (l to 3 days old) were isolated and cultured with indicated concentration of Hcy for different duration. [3H]-thymidine ([3H]-TdR) incorporation was assayed, and protein amount of myocardial cells was determined by Lowry method. The [Ca2+]i was quantitated with fluorescent dye Fura-2/AM spectrofluorometry. Results When myocardial cells were incubated with Hcy, increase of incorporation of [3H] -TdR was observed in a dose- and time-dependent manner. Meanwhile, dose-dependent elevation of [Ca2+] i in myocardial cells was induced by Hcy. Conclusions Hcy induces proliferation of myocardial cells and increases level of [Ca2+] i. Hyperhomocysteine may be implicated in uremic myocadial disease.