Effect of Uncariae ramulus et Uncus on endothelium in spontaneously hypertensive rats

The protective effect of the extract of Uncariae ramulus et Uncus (URE) aga inst endothelium disorder due to hypertension was investigated. We administ ered low (150 mg/kg/day) and high (450 mg/kg/day) doses of URE orally to sp ontaneously hypertensive rats for 8 weeks. Endothelium dependent vasodilata tion by acetylcholine increased significantly in the high URE group compare d with the control group. Endothelium dependent vasocontraction by xanthine oxidase decreased significantly in the high URE group compared with the co ntrol group. Serum NO2-/NO3- were tended to increase in the high URE group. It is suggested that URE may have a protective effect for the endothelium against the influence of hypertension.