丹参酮对肥大心肌细胞中电生理特征和钙调神经磷酸酶活性的作用

Action of tanshinone on electrophysiological abnormality and calcineurin activity in hypertrophy cardiomyocyte

目的观察丹参酮对肥大心肌细胞中电生理特征和钙调神经磷酸酶(CaN)活性的作用。方法通过膜片钳、胞内钙测定和分子生物学技术,观察丹参酮对"一肾一夹"手术导致的肥厚心肌细胞膜上动作电位时间、L型钙通道电流(ICa,L)、胞内钙离子浓度以及CaN活性的影响。结果丹参酮可以显著缩短肥厚心肌细胞中存在的动作电位时间延长(P<0.001)、降低膜电容和ICa,L峰值幅度(P均<0.001),但不影响ICa,L密度,并能够显著减少胞内钙离子浓度。丹参酮能显著抑制肥厚心肌中CaN的表达(P<0.05)。结论丹参酮可以有效地减少肥大细胞中的Ca2+浓度并抑制L-型钙通道,并使肥大心肌细胞中的CaN活性降低,从而改善肥大心肌细胞中存在的电生理异常和减轻心肌肥厚的发生。

Objective It is to observe the action of tanshinone on electrophysiological abnormality and calcineurin（CaN） activity in hypertrophy cardiomyocyte.Methods The influence of tanshinone on action potential duration,L-type calcium channels current（ICa,L）,intra-cellular calcium ion concentration and CaN activity in cellular membrane of hypertrophic myocardium induced by the surgery of ＂one kidney one clamp＂ was observed through patch clamp,intra-cellular calcium mensuration and molecular biological technique.Results Tanshinone could markedly shorten the prolongation of action potential duration（P0.001）,lower membrane capacity and peak amplitude of ICa,L（P0.001） and markedly reduce intra-cellular calcium ion concentration,but not affect the density of ICa,L.Tanshinone could markedly inhibited CaN expression of hypertrophic myocardium（P0.05）.Conclusion Tanshinone can effectively reduce calcium ion concentration,inhibit L-type calcium channels and lower CaN activity in hypertrophic cadiocyte so that it may improve electrophysiological abnormality and alleviate the occurrence of myocardial hypertrophy.