The endothelium plays an important role in the regulation of vascular tone and regulation of
blood flow. Nitric oxide (NO) is the most important known endothelium-derived vasodilating
factor. Prospective studies have shown that hypercholesterolemia impairs endothelial function
in different vascular beds. Lowering total cholesterol and particularly LDL-cholesterol with
statins leads to an improvement in endothelium-dependent vasodilation in the forearm
vasculature. There is strong evidence to suggest that the benefit is not merely related to
the decrease in cholesterol-levels. A recent study in the forearm vasculature demonstrated
that short-term lipid-lowering therapy improves endothelial function and NO availability
already after 3 days of lipid lowering therapy. Whether endothelial function in the renal
vasculature of hypercholesterolemic patients is similarly influenced has not yet been
addressed adequately. In the present study we investigate whether lipid lowering therapy with
rosuvastatin alters renal endothelial function, as assessed by systemic infusion of the NO
synthase inhibitor L-NMMA, after 3 and 42 days of therapy.