Abstract: AIM:To investigate the effects of androgen deficiency on vascular endothelial cell function and structure in castrated male rats.METHODS:Twenty male Wistar rats were randomly divided into simple castrated group(n=10) and sham-operated group(n=10).Blood testosterone concentration,nitric oxide(NO) and endothelin-1(ET-1) were tested after 8 weeks.Pathological changes of thoracic aorta vascular endothelial cell were observed with HE stain.RESULTS:Compared with those in sham-operated group,testosterone concentration was significantly lower in simple castrated group(P<0.05) and blood plasma NO content in simple castrated group showed an obvious degradation (33.44±8.50) μg/L vs.(21.61±10.51) μg/L,P<0.05.ET-1 levels of castrated group were significantly higher than the sham-operated group (4.41±0.34) μg/L vs.(3.84±0.16) μg/L,P<0.05.Vascular smooth muscle cells in simple castrated group were of irregular arrangement and uneven wall thickness and vascular endothelial cells showed significant proliferation.CONCLUSIONS:Vascular endothelial cells in castrated male rats can be injured after androgen deficiency,with reduced NO and increased ET-1.