ABSTRACT
Aim To evaluate the endothelial dysfunction level of different arteries at different stages of SHR,and the recovery after administration.Methods SHR model was used,captopril(3.375 g·kg~(-1)·d~(-1)) was administered from week 7 to week 24 and the effects were observed continuously until 8 weeks post treatment.Pathological changes of aorta,mesenteric and apex cordis arteries were examined at the time points of 6,18,24,32 wk,and the endothelial-dependent relaxation of the former two preparations were tested by acetylcholine(ACh)(n=6).Results There were pathological changes in the thoracic aorta,mesenteric artery and arteriole at 18 wk,and aggravated along the age.The thoracic aorta demonstrated the most severe pathological changes appearing endothelial cells ablated and tunica media thickening.The significant decline of endothelium-dependent relaxation in aorta,and mesenteric arteries of SHR reflected an aging dependent change of vascular function with the most severe situation in the aorta(P=0.10,18 wk,P<0.01 24,32 wk);captopril increased the aorta vasodilatation of SHR at 18 wk time point,without the effect in mesenteric artery(P<0.05 vs SHR).Conclusions During the progress of SHR,endothelial damages have been observed in all three kinds of vasculatures together with the reduced endothelial-dependent relaxation.The aorta presents earlier and deeper damage than middle and small size vessels,and is sensitive towards the antihypertensive therapy such as the angiotensin converting enzyme inhibitor.