高血压导致动脉弹性减退的病理学机制

The pathologic mechanism underlying hypertension-induced decline in arterial elasticity

目的探讨高血压对大动脉弹性容量顺应性（C1）、小动脉弹性振荡顺应性（C2）和升主动脉中膜组织结构成分的影响及动脉弹性与升主动脉中膜组织结构成分的相关性。方法人选在我院行冠状动脉旁路移植术的冠心病患者60例，分为高血压组和非高血压组（各30例）。测定C1和C2。将冠状动脉旁路移植术中从升主动脉前壁取下的组织进行病理切片，分别用Masson染平滑肌和胶原纤维，Weigert间苯二酚复红法染弹性纤维。光镜下以计算机图像分析系统测定血管平滑肌、胶原纤维和弹性纤维的相对面积。C1、C2与升主动脉组织结构成分间的相关性应用直线相关分析。结果高血压组患者大动脉弹性指数C111．9±1．8（ml／mmHg×10），1mmHg=0．133kPa，低于非高血压组13．1±2．5（ml／mmHg×10），t=2．22，P〈0．05；升主动脉壁中膜胶原纤维的相对含量高血压组患者（46．0±3．8）％较非高血压组（42．2±3．0）％升高（t=4．24，P〈0．01），弹性纤维高血压组（17．5±3．5）％，较非高血压组患者（19．3±2．7）％减少（t=2．20，P〈0．05）。高血压组和非高血压组大动脉弹性C1均与弹性纤维的相对含量呈正相关（r值分别为0．52、0．39，P〈0．05和P〈0．01），而与胶原纤维的相对含量呈负相关（r值分别为一0．55、0．67，均P〈0．01）。结论高血压可导致冠心病患者大动脉弹性下降，其主要病理基础是胶原纤维增多和弹性纤维减少及主要成分的排列紊乱。大动脉弹性C1可准确反映高血压对升主动脉中膜胶原纤维和弹性纤维的影响。

Objective To investigate the effect of hypertension on the large artery elasticity index （C1）, the small artery elasticity index （C2） and the medial structure of the ascending aorta as well as the relationship between artery elasticity and the medial structure of the ascending aorta. Methods Sixty patients with CHD receiving coronary artery bypass graft surgery at our hospital were divided into two groups： 30 patients in the hypertension group and 30 patients in the non-hypertension group. C1 and C2 were measured using the CVProfilor DO-2020 system. Sections of tissues taken from the anterior wall of the ascending aorta during the surgery were subjected to Masson＇s trichrome staining for the detection of vascular smooth muscle and collagen fibers and Weigert＇s resorcin fuchsin staining for the detection of elastic fibers. The relative areas of vascular smooth muscle fibers, collagen fibers and elastic fibers of the ascending aorta were measured by a computer image analysis system under the light microscope. The linear correlations of C1 and C2 with the medial structure of the ascending aorta were analyzed. Results C1 in the non-hypertension group was higher than that in the hypertensiongroup[11. 9±1. 8 （ml/mmHg×10） vs 13.1±2.5 （ml/mmHg×10）, t=2.22, P 〈0. 05]. In the media of the ascending aorta, the relative content of collagen fibers was higher, while the relative content of elastic fibers was lower in the hypertension group than in the non-hypertension group [（46.0±3.8）% w （42.2±3.0）%, （17.54±3.5）% vs（19.3 2.7）%, respectively, t=4.24 and 2.20, P〈0.01 or 0.05]. C1 was positively correlated with the relative content of elastic fibers but negatively correlated with the relative content of collagen fibers in both groups （r=0.52 and 0.39, respectively, P〈0. 05 or 0. 01）. Conclusions The main pathogenic basis of hypertension-induced decline in arterial elasticity in CHD patients is increased collagen fibers and reduced elastic fibers with disorganization of the two types of components. C1 may accurately reflect the effect of hypertension on medial collagen fibers and elastic fibers in the ascending aorta.