Endothelial- and nitric oxide-dependent effects on oxidative metabolism of intact artery.
Oxidative metabolism and its possible modulation by nitric oxide (NO) was examined in endothelial-intact and endothelial-denuded segments of porcine carotid arteries. Endothelial-intact arteries displayed appropriate NO-mediated vasorelaxation to acetylcholine (ACh). Endothelial-denuded arteries demonstrated absent vasorelaxation to ACh stimulation and depressed contractile responsiveness to K(+) depolarization, which was normalized by inhibition of NO synthesis by N(omega)-nitro-L-arginine methylester (L-NAME). Confirmation that carotid arteries continued to produce NO despite removal of the endothelium was indicated by detection of NO metabolites in the incubation medium bathing the arteries. O(2) consumption and the oxidation of glucose and fatty acid were depressed in endothelial-denuded arteries. Depression of O(2) consumption and glucose oxidation was completely reversed by treatment with L-NAME. We conclude that endogenous NO produced by non-endothelial vascular cells depresses contractility, O(2) consumption, and oxidation of energy substrates in vascular smooth muscle. The endothelium may play a role in oxidative metabolism of vascular smooth muscle possibly by modulating the effects of NO produced by other cells of the vessel wall, or by other factors.
Barron
J T
JT
Section of Cardiology, Department of Internal Medicine, Rush Medical College, Rush-Presbyterian-St. Luke's Medical Center, 1653 West Congress Parkway, Chicago, IL 60612, USA. jbarron@rush.edu
Gu
L
L
Parrillo
J E
JE
D000109:Acetylcholine; D000818:Animals; D002339:Carotid Arteries / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D066298:In Vitro Techniques; D009119:Muscle Contraction; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000494:pharmacology*; D009573:Nitrites / Q000032:analysis; D009638:Norepinephrine; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D013552:Swine; D013997:Time Factors; D014664:Vasodilation
D005227:Fatty Acids; D009573:Nitrites; D009569:Nitric Oxide; D005947:Glucose; D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine