慢性肾脏病大鼠血管收缩张力与血管钙化的关系

Relationship between vascular contraction tone and calcification in chronic kidney disease rats

目的通过检测慢性肾脏病(CKD)大鼠血管收缩张力,探讨其与血管钙化的关系。方法 30只雄性SD大鼠随机分为3组:正常对照组、慢性肾脏病组(CKD组)及慢性肾脏病血管钙化组(CKD+VC组),第4周留取血清学及血管标本,采用离体血管环灌流方法测定胸主动脉张力,硝酸银染色(Von Kossa染色)、钙含量测定和EVG染色检测血管钙化和弹性纤维变化情况,电镜观察平滑肌细胞(VSMCs)的超微结构。结果①CKD+VC组的血管收缩张力与正常对照组比较,最大值(Emax)下降(P=0.001),半数有效浓度(EC50)差异无统计学意义(P>0.05);与CKD组相比,Emax与EC50均无统计学意义(P>0.05)。②光镜结果显示,CKD+VC组可见弹性纤维严重断裂和钙盐沉积,CKD组可见弹力纤维排列紊乱、变细,未见钙盐沉积;电镜结果显示,模型组均可见凋亡VSMCs。结论 VSMCs凋亡和弹性纤维断裂共同参与CKD大鼠胸主动脉张力的下降,而血管钙化对张力的变化无影响。

【Objective】 To explore the relationship between thoracic aortic contraction tone and vascular calcification in chronic kidney disease（CKD） rats. 【Methods】 30 male SD rats were divided into 3 groups randomly： normal control group, chronic kidney disease group and chronic kidney disease group with vascular calcification. 4 weeks later, Plasma and aortic samples were taken, using isolated vascular ring perfused method for determining the tone of the thoracic aorta. Von Kossa, calcium content and EVG staining test thoracic aortic calcification and change of the elastic fibers, electron microscopic observe the ultrastructure of vascular smooth muscle cells（VSMCs）. 【Results】 In vitro thoracic aorta tone change, compared with normal group, the Emax values are decreased（P =0.001） and the EC50 values are without change（P〉0.05） in CKD with vascular calcification group, while comparing with CKD group, the Emax and EC50 values are not change obviously（P〉0.05）. The light microscope showed media elastic fiber severe fracture and calcium salt deposit in CKD with vascular calcification group, while elastic fiber arranged disorder, thinning and broken, no calcium salt deposition in CKD group; Electron microscopy results showed that vascular smooth muscle cells apoptosis in the two model groups. 【Conclusion】 VSMCs apoptosis and elastic fibers break both take part in the thoracic aorta tone decline in the CKD rats with vascular calcification, while calcium salt deposition has no effect on vascular tone.