二十二碳六烯酸对心房颤动大鼠心房肌细胞双孔钾通道TASK-1表达的影响

The effects of docosahexaenoic acid on two- pore domain potassium channel TASK-1 protein expression in atrial myocytes of atrial fibrillation rats

目的探讨二十二碳六烯酸(DHA)在大鼠心房颤动(房颤)模型中的作用及其对双孔钾离子通道TASK-1表达的影响。方法 SD雄性大鼠分为4组:(1)对照组:每天注射等体积生理盐水;(2)DHA组:每天注射等体积DHA;(3)房颤组:每天给予乙酰胆碱+氯化钙混合液建立房颤模型;(4)房颤DHA组:每天先给予DHA,半小时后建立房颤模型,方法同房颤组。分别观察各组大鼠房颤发生时间和检测心房有效不应期(ERP);应用Western blot测定大鼠心房肌中TASK-1蛋白表达及RT-PCR测定大鼠心房肌中TASK-1 mRNA表达。结果房颤DHA组较房颤组大鼠心房颤动出现时间明显推迟,稳定时间提前,分别为第3天和第1天出现,第8天[(22±5.0)s]比第10天[(35±5.3)s]稳定;每天房颤持续时间显著缩短,与对照组相比,房颤组ERP明显缩短[从(77.3±6.0)s到(60.4±4.3)s],与DHA组相比,房颤DHA组ERP显著缩短[从(90.8±3.4)s到(82.4±5.7)s];与对照组相比,DHA组TASK-1 mRNA和蛋白表达降低,房颤组及房颤DHA组TASK-1 mRNA和蛋白表达水平升高;与房颤组相比,DHA组及房颤DHA组TASK-1 mRNA和蛋白表达降低。结论 DHA具有抗房颤作用,其机制可能与下调双孔钾离子通道TASK-1蛋白表达有关。

Objective To explore the role of docosahexaenoic acid （DHA） in the rat model of atrial fibrillation,and its effect on two - pore domain potassium channel TASK - 1 protein expression. Methods SD male rats were ran-domly divided into control group （Con）, DHA treatment control group （DHA） , AF group （AF）, and atrial fibrillationDHA treatment group （ AF ＋ DHA）. The duration of atrial fibrillation and the atrial effective refractory period （ERP）were measured. The TASK - 1 protein expression levels of the rat atrial muscle were detected using Western blot, and themRNA expression levels of TASK - 1 of the rat atrial muscle were detected by reverse transcriptase - polymerase chain re-action. Results The onset of atrial fibrillation in DHA ＋ AF group was later than that in AF group （ the 3ra day vs the 10th day）. Moreover, the time of atrial fibrillation stabilization in DHA ＋ AF group was more advanced than that in AF group（the 8th, day vs the 10th day） , with shortened duration of atrial fibrillation. The atrial ERP in AF group was significantlyshorter than that in Con group [ （ 60.4 ±4. 3 ） ms vs （77.3±6. 0） ms ], and the atrial ERP in AF ＋ DHA group was signif-icantly shorter than that in DHA group [ （90. 8 ± 3.4） s vs （82.4 ± 5.7） s]. Compared with Con group, TASK - 1 mRNAand protein were significantly down - regulated in DHA group, but up - regulated in AF and DHA ＋ AF groups. Comparedwith AF group, TASK - 1 mRNA and protein were significantly down - regulated in AF and DHA ＋ AF groups. Conclu-sion DHA may play the role of anti - atrial fibrillation in atrial fibrillation rat model, which may be associated with re-ducing two - pore domain potassium channel TASK - 1 protein and mRNA expression.