年龄增加对人血管内皮依赖性舒张作用的实验研究及机制探讨

目的探讨年龄增加对人血管内皮依赖性舒张作用的影响及其初步机制。方法采用血管环张力测定法，在15例不同年龄段（51~83岁）胃癌患者手术切除的胃网膜动脉上，测定0.001~10 μmol/L乙酰胆碱（ACh）诱发的血管内皮依赖性舒张作用和内皮依赖性超级化因子（EDHF）样血管舒张作用的变化；采用实时荧光定量PCR（qRT-PCR）方法观察不同年龄人血管中的内皮型NO合酶（eNOS）、环氧合酶（COX）、胱硫醚γ裂解酶（CSE）以及C-型利钠肽（CNP）基因表达的改变。结果相同剂量下，ACh诱导出人动脉内皮依赖性的舒张作用会随着年龄的增加而减弱（P<0.05），其EDHF样血管舒张作用也明显降低（P<0.05）；qRT-PCR发现随着年龄的增加，其血管eNOS、CSE和CNP mRNA表达降低(P<0.05)，而COX mRNA表达的年龄趋势不明显。结论随年龄的增加，血管内皮依赖性舒张和EDHF样舒张作用降低，可能与内皮合成的NO和CNP等舒血管物质减少有关。

Effects of Aging on Endothelium-dependent Vasodilation of Human Artery

ObjectiveTo determine the effects of aging on endothelium-dependent vasodilation of human artery. MethodsVessel tension changes induced by acetylcholine (ACh) and endothelial-derived hyperpolarizing factor (EDHF) on gastroepiploic artery rings were recorded in 15 patients with stomach cancer aged between 51 and 83 years. The mRNA expressions of endothelial nitric oxide synthase (eNOS),cyclooxygenase (COX),cystathionineγ lyase (CSE) and the C-type natriuretic peptide (CNP) in the artery vessels were detected by qRT-PCR. ResultsBoth endothelium-dependent and EDHF induced vasodilation decreased with age (P<0.05). The mRNA expressions of eNOS,CSE and CNP also decreased with age (P<0.05),except COX. ConclusionAging could impair the function of endothelium-dependent vasodilation and EDHF-induced vasodialtion of human artery,possibly due to decreased NO,H2S and CNP in artery.