Endothelial function has been shown to be defective in hyperlipidaemic patients, and animal studies have suggested that Angiotensin Converting Enzyme (ACE) Inhibitors may prevent arterial damage. In order to see if this also occurs in man, we studied the effect of six months treatment with lisinopril on endothelial function in a group of hypercholesterolaemic patients. METHODS and RESULTS: 40 patients were recruited. Forearm Despite a normal cardiac response to ere was a fall in BP. The failure to increase calf vascular resistance due to the action of insulin on skeletal muscle vasculature may be responsible for postprandial hypotension in the elderly after HC.blood flow via venous occlusion plethysmography was assessed in response to Acetylcholine, and Sodium Nitroprusside. Subjects were then randomised in a double blind fashion to receive either Lisinopril 20mg/day (n=20). or placebo (n=20) for six months. Plethsymography was then repeated. Baseline variables between groups were comparable. Lisinopril group: Blood pressure fell significantly, systolic 145k4 vs. 12854 (P