Role of ageing on rat endothelial dysfunction / 中国医师杂志

ABSTRACT

Objective Alterations in vascular structure and function and impairment of associated endothelial cells with aging are one of the independent risk factors in the process of atherosclerotic vascular diseases.The study of age-related endothelial dysfunction plays a critical role in preventing as well as treating heart and cerebral vascular diseases in the elderly.Methods The healthy male rats were divided into the young group (3-month-old),the adult group (9-month-old) and the middle-aged group (15-monthold).The indicators associated with vascular endothelial function,including plasma NO,eNOS,iNOS,ET-1 and aortic NO,eNOS,iNOS,were quantified to evaluate the endothelium-dependent and non-endothelium-dependent vasodilating function of isolated aortic rings.These morphological changes of rat aorta helped to find out the group in which endothelial function changed in the early stage.Results Plasma NO,eNOS,iNOS and aortic NOS activity in the young group,the adult group and the middle-aged group gradually decreased with increasing age (P ＜ 0.05).NO,eNOS and iNOS respectively displayed a negative correlation to age.ET-1 gradually increased with aging (P ＜ 0.05) and showed a predominantly positive correlation to age.Acetylcholine-induced greatest vasodilation of aortic rings lessened with increasing age (P ＜ 0.05).Vasodilation in each group reacted generally consistently with nitroprusside sodium (P ＞0.05).Aortic morphology,including intima media thickness (T),diameter (D) and intima media thickness / inner diameter (T / D),gradually enhanced with aging (P ＜ 0.05).T,D was positively correlated with age.NO,eNOS,iNOS,ET-1 of the adult group showed maximum slope (P ＜0.05 respectively) according to group regression analysis,suggesting that vascular endothelial function changed in this group.Meanwhile,T and D of the middle-aged group showed maximum slope (P ＜ 0.05 respectively),suggesting that age-related vascular structural changes predominantly occurred in this period and vascular function changed earlier than the structure.Conclusion Our study demonstrated vascular endothelial dysfunction with aging.Early evident changes of endothelial function occurred in the adult group,which impaired endothelium-dependent vasodilating function.Vascular function changed earlier than the structure.