Oxidized low density lipoproteins potentiate vasoconstrictions to various agonists by direct interaction with vascular smooth muscle.

摘要: In hypercholesterolemia, low density lipoproteins (LDLs) may be oxidized by monocytes/macrophages in the arterial wall. Therefore, we investigated effect of LDL and its oxidative derivatives (ox-LDL) on vascular tone isolated perfused rabbit femoral arteries. Perfusion endothelium-intact endothelium-denuded segments with ox-LDL (80 micrograms protein/ml) caused no or only weak vasoconstrictions absence contractile agonists. However, presence ox-LDL, to threshold concentrations norepinephrine, serotonin, phenylephrine, potassium were significantly enhanced. This enhancement correlated degree oxidation. When was administered at higher (greater than 200 protein/ml), it evoked moderate even Native had tone. Preincubation verapamil, diltiazem, nitrendipine inhibited both a agonist. The responses greater segments. At above concentrations, influence endothelium-derived relaxing factor-mediated vasodilations. These data indicate that enhances agonist-induced direct smooth muscle. We therefore suggest is an important factor increase risk inappropriate vasoconstriction independent putative cytotoxic endothelium.