title: High density lipoprotein and low density lipoprotein attenuate the inhibitory effects of oxidized low density lipoprotein on endothelium-dependent arterial relaxation.
abstract: We have recently reported that oxidized low density lipoprotein (ox-LDL) inhibits endothelium-dependent arterial relaxation through its increased lysophosphatidylcholine (LPC). In this study we examined whether high density lipoprotein (HDL) as well as native low density lipoprotein have any effects on the inhibition of endothelium-dependent relaxation by ox-LDL in isolated strips of rabbit thoracic aorta. Both LDL and HDL were isolated from normal human plasma and LDL was oxidized by exposure to copper. Preincubation of arterial strips with ox-LDL (0.1-0.5 mg protein/ml) inhibited endothelium-dependent relaxation to acetylcholine (ACh) in a concentration-dependent manner. HDL (1 mg protein/ml) by itself had no effect on the relaxation to ACh. In the presence of HDL, the inhibition by ox-LDL was markedly reduced. In addition, native LDL also attenuated the inhibition of endothelium-dependent relaxation by ox-LDL. Thus, HDL and native LDL may have salutary effects against the impairment of endothelium-mediated vasodilation in atherosclerotic arteries.
authors.affiliation: Department of Internal Medicine, Kobe University School of Medicine.
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
mesh_terms: D000109:Acetylcholine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D008077:Lipoproteins, LDL / Q000737:chemistry / Q000494:pharmacology*; D010084:Oxidation-Reduction; D011817:Rabbits; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
chemical_list: D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D000109:Acetylcholine