丹参酮对肥厚心肌组织中钙调神经磷酸酶的影响

摘要

目的:通过腹主动脉缩窄所致心肌肥厚模型,探讨丹参酮的抗心室重构与钙调神经磷酸酶信号通路的关系.方法:SD大鼠通过腹主动脉缩窄建立高血压的心肌肥厚模型,4周后将手术大鼠分为手术组(B组),丹参酮低剂量组[C组,10 mg/(kg·d)],丹参酮高剂量组[D组,20 mg/(kg·d)]及缬沙坦组[E组,10 mg/(kg·d)],每组各8只,另有8只SD大鼠作为假手术组(A组).用药8周后检测各组尾动脉压,取左心室组织检测左心室质量指数(LVMI),病理切片HE染色测量心肌纤维直径(MFD),采用逆转录-聚合酶链式反应法检测AT1受体 mRNA表达,采用免疫印迹法检测AT1受体和CaN的蛋白表达,通过Fura-2双波长荧光法检测心肌细胞内游离Ca2+浓度.结果:与A组和E组比较,B、C、D组的血压值显著升高,差异有高度统计学意义(P＜0.01),B、C、D组间血压差异无统计学意义(P＞0.05).C、D、E组的LVMI、MFD值均高于A组,且显著低于B组,差异均有统计学意义(P＜0.05).与其他各组相比,AT1受体蛋白和mRNA水平在B组中表达最高,差异有高度统计学意义(P＜0.01),而C、D组间表达差异无统计学意义(P＜0.05),但均高于E组,差异有统计学意义(P＜0.05),C、D、E组的AT1受体 mRNA表达水平均未降至A组水平,差异有统计学意义(P＜0.05).B组的CaN蛋白表达水平较其他各组明显升高,差异有统计学意义(P＜0.05),且丹参酮对其表达的干预呈剂量依赖性,D、E组间CaN蛋白表达差异无统计学意义(P>0.05).B组细胞内Ca2+浓度明显高于其他各组,差异有高度统计学意义(P＜0.01),但D、A组间差异无统计学意义(P＞0.05),E、C组Ca2+浓度均高于A、D组,差异有高度统计学意义(P＜0.05).结论:丹参酮可通过阻止心肌细胞的钙离子内流,减少钙调神经磷酸酶的表达,起到抑制心肌肥厚的作用.%Objective: To explore the relationship between Tanshinone resistance left ventricular remodeling and cal-cineurin signal pathway by the rat models of myocardial hypertrophy which were caused by abdominal aortic coarctation. Methods: SD rats were operated with abdominal aorta constriction to construct the model of myocardial hypertrophy. After 4 weeks, model rats were divided into four groups: artificial operation group (group B), low dose Tanshinone group [group C, 10 mg/(kg· d)], high dose Tanshinone group [group D, 20mg/(kg·d)] and Valsartan group [group E, 10mg/(kg·d)], each of 8 cases and 8 rats were divided into sham operation group (group A). 8 weeks later, tail arterial pressure and the left ven -tricular mass index (LVMI) were measured, and myocardial fiber dimension (MFD) which were stained with HE reagent al -so was measured. AT1 receptor Mrna expression was detected by RT-PCR. AT1 receptor and CaN protein expression were detected by western blotting in left ventricular tissues of all groups. [Ca2+]I was observed by Fura-2 double wavelengths fluorescence method. Results: The blood pressure in group B, C, D were obviously higher than that in group A and group E, the difference was statistically significant (P<0.01), But there was no statistical difference between group B, C and D (P>0.05). The LVMI and MFD vaule were obviously higher in group C, D, E than that of group A, and lower than that of group B, the differences were statistically significant (P<0.05). The protein and Mrna expression of AT] receptor in group B were the highest in all groups, the differences were statistically significant (P<0.01), and there was no statistical different between group C and D (P>0.05), which was higher than group E, the difference was statistically significant (P<0.05). But the Mrna expression in group C, D and E were not recovered to the normal level (group A), the differences were statistically significant (P< 0.05). The protein expression of CaN in group B was obviously higher than that of other groups, the differences were statis -tically significant (P<0.05), and the interventions of Tanshinone were dose-dependent. There was no statistical differencebetween group D and group E (P>0.05). The concentration of [Ca2+]I in group B was higher than other groups, the differences were statistically significant (P<0.01), and therewas no statistical difference between group D and group A (P>0.05) , but the concentration of [Ca2+]I in group E and group C were higher than that of group A and D, the differences were statistically significant (P<0.05). Conclusion: Tanshinone can resist the myocardial hypertrophy by blocking the inflow of calciumion and downregulating the protein expression of CaN in cadiocyte .