代谢综合征和自发性高血压大鼠血管结构及功能差异的研究

目的观察代谢综合征（MS）大鼠大、中、小动脉结构和功能的改变，明确MS的血管损害特征。方法将实验大鼠分为MS组、正常对照组（NC）、自发性高血压组（SHR）、高血压对照组（WKY）。以HE染色进行形态学观察，并检测离体主动脉环反应性和主动脉eNOS、iNOS、RhoA／ROCK蛋白含量。结果除血管壁增厚、内膜和平滑肌细胞增生外，MS大鼠的大、中动脉有明显炎细胞浸润，小动脉出现玻璃样变性，与SHR形成区别。MS大鼠血管环舒张功能较NC组明显减弱，而SHR的收缩反应较WKY组显著增强。MS大鼠主动脉的RhoA、ROCK表达增多，但较SHR少，eNOS和iNOS表达两组均减少，组间无明显差异。结论MS时动脉结构和功能的损害较SHR更为严重和广泛，其分子机制与RhoA、ROCK系统的激活和NOS表达减少有关。

A study on differences in vascular structure and function between spontaneous hypertension and metabolic syndrome in rat

Objective To investigate the features of vascular damage in metabolic syndrome (MS) by a comparison of changes in vascular structure and function between spontaneous hypertension (SH) and MS in rats. Methods Pathological study of changes in arteries was carried out. The contractile response of aorta ring and the expression of RhoA, ROCK, eNOS and iNOS were also determined. Results Besides the thickening of arterial wall and proliferation of both intima and smooth muscle layer, marked infiltration of inflammatory cell appeared in large and medium arteries of MS rats, and obvious hyaline degeneration was found in mesenteric arterioles. Moreover, the relaxant response of aorta ring was weakened markedly in MS rats, while the contractile response increased in SH rats dramatically. The expression of RhoA, ROCK increased and that of NOS decreased in MS rats, but the up-regulation of the RhoA, ROCK expression was not as much as in SH rats. Conclusion The damage to both arterial structure and function was much more serious in MS rats than that in SH rats. Activation of RhoA/ROCK system and reduction of NOS expression might be involved in the mechanism.