RhoA/ROCK信号通路对高糖致大鼠冠状动脉舒缩功能损伤的影响

Effect of RhoA/ROCK signal pathway on small coronary arteries impairment of rats induced by high glucose

目的探讨RhoA/ROCK信号通路对高糖致大鼠冠状动脉舒缩功能损伤的影响。方法分离雄性Sprague Dawley大鼠的小冠状动脉并制作血管环,将血管环随机分为正常葡萄糖组、左旋葡萄糖组、高葡萄糖组、高葡萄糖+C3转移酶组和高葡萄糖+Y-27632组。正常葡萄糖组血管环给予5. 5 mmol·L^(-1)D-葡萄糖培养24 h;左旋葡萄糖组血管环给予5. 5 mmol·L^(-1)D-葡萄糖和17. 5 mmol·L^(-1)L-葡萄糖培养24 h;高葡萄糖组血管环给予23. 0 mmol·L^(-1)D-葡萄糖培养24 h;高葡萄糖+C3转移酶组血管环给予23. 0 mmol·L^(-1)D-葡萄糖培养24 h,C3转移酶处理16 h;高葡萄糖+Y-27632组血管环给予23. 0 mmol·L^(-1)D-葡萄糖培养24 h,Y-27632预处理16 h。各组取部分血管环,观察其对3. 0 mmol·L^(-1)4-氨基吡啶(4-AP)的收缩反应和对1μmol·L^(-1)佛司可林的舒张反应;另取部分血管环制作石蜡切片,采用免疫组织化学法检测各组大鼠小冠状动脉中RhoA、ROCK1和ROCK2蛋白的表达。结果与正常葡萄糖组相比,高葡萄糖组大鼠小冠状动脉的收缩力和舒张反应均显著降低(P <0. 05);高葡萄糖+C3转移酶组和高葡萄糖+Y-27632组大鼠小冠状动脉的收缩力和舒张反应均高于高葡萄糖组(P <0. 05);高葡萄糖+C3转移酶组与高葡萄糖+Y-27632组大鼠小冠状动脉收缩力和舒张反应比较差异无统计学意义(P> 0. 05)。与正常葡萄糖组比较,高葡萄糖组大鼠小冠状动脉中RhoA、ROCK1和ROCK2蛋白表达均显著升高(P <0. 05);高葡萄糖+C3转移酶组和高葡萄糖+Y-27632组大鼠小冠状动脉中RhoA、ROCK1和ROCK2蛋白表达均低于高葡萄糖组(P <0. 05);高葡萄糖+C3转移酶组与高葡萄糖+Y-27632组大鼠小冠状动脉中RhoA、ROCK1和ROCK2蛋白表达比较差异无统计学意义(P>0. 05)。结论高糖可激活RhoA/ROCK信号传导通路,引起大鼠小冠状动脉中RhoA、ROCK1、ROCK2蛋白表达增加;RhoA/ROCK通路参与了高糖致大鼠冠状动脉舒缩功能损伤的过程。

Objective To explore the effect of RhoA/ROCK signal pathway on small coronary arteries impairment of rats induced by high glucose.Methods The small coronary arteries of rats were dissected for making vascular ring.Then the vascular ring were randomly divided into normal glucose group,levoglucose group,high glucose group,high glucose+C3 transferase group and high glucose+Y-27632 group.The vascular rings in normal glucose group were cultured with 5.5 mmol·L^-1 D-glucose for 24 hours,the vascular ring in levoglucose group were cultured with 5.5 mmol·L^-1 D-glucose and 17.5 mmol·L^-1 L-glucose for 24 hours,the vascular ring in high glucose group were cultured with 23.0 mmol·L^-1 D-glucose for 24 hours,the vascular ring in high glucose+C3 transferase group were cultured with 23.0 mmol·L^-1 D-glucose for 24 hours and treated with C3 transferase for 16 hours,the vascular ring in high glucose+Y-27632 group were cultured with 23.0 mmol·L^-1 D-glucose for 24 h and pretreated with Y-27632 for 16 hours.A partment of vascular rings were taken to observe their contractile response to 4-aminopyridine(4-AP)at 3.0 mmol·L^-1 and the diastolic response to 1.0μmol·L^-1 foscolin in each group.Another partment of vascular rings were taken to make the paraffin section,and the expression of RhoA,ROCK1 and ROCK2 protein in the small coronary arteries of rats in each group was detected by immunohistochemistry.Results Compared with the normal glucose group,the systolic force and diastolic response of the small coronary artery of rats in the high glucose group were significantly lower(P<0.05);the systolic force and diastolic response of the small coronary artery of rats in the high glucose+C3 transferase group and the high glucose+Y-27632 group were significantly higher than those in the high glucose group(P<0.05);there was no significant difference in systolic force and diastolic response of the small coronary artery of rats between the high glucose+C3 transferase group and the high glucose+Y-27632 group(P>0.05).Compared with the normal glucose group,the expression of RhoA,ROCK1 and ROCK2 protein in the small coronary artery of rats in the high glucose group increased significantly(P<0.05);the expressions of RhoA,ROCK1 and ROCK2 protein in the high glucose+C3 transferase group and the high glucose+Y-27632 group were significantly lower than those in the high glucose group(P<0.05);there was no significant difference in the expression of RhoA,ROCK1 and ROCK2 protein in the small coronary artery of rats between the high glucose+C3 transferase group and the high glucose+Y-27632 group(P>0.05).Conclusion High glucose can activate RhoA/ROCK signal transduction pathway and increase the expression of RhoA,ROCK1 and ROCK2 protein in small coronary artery of rats.RhoA/ROCK pathway is involved in the process of impairing diastolic and systolic function of small coronary artery of rats induced by high glucose.