Ceramide-induced activation of NADPH oxidase and endothelial dysfunction in small coronary arteries. Am J Physiol Heart Circ Physiol 2003 Feb;284(2):H605-12
Date
11/09/2002Pubmed ID
12424096DOI
10.1152/ajpheart.00697.2002Scopus ID
2-s2.0-0037306287 88 CitationsAbstract
We tested the hypothesis that ceramide induces endothelial dysfunction in small coronary arteries via NADPH oxidase-mediated superoxide and resulting peroxynitrite formation. With the use of dihydroethidium as a superoxide indicator, C(2)-ceramide was found to increase superoxide production in the endothelial cells of small coronary arteries, which was inhibited by the NADPH oxidase inhibitors N-vanillylnonanamide, apocynin, and diphenylene iodonium. NADPH oxidase expression was confirmed in endothelial cells, as indicated by the immunoblotting of its subunits gp91(phox) and p47(phox). C(2)-ceramide increased NADPH oxidase activity by 52%, which was blocked by NADPH oxidase inhibitors but not by inhibitors of NO synthase, xanthine oxidase, and mitochondrial electron transport chain enzymes. By Western blot analysis, ceramide-induced NADPH oxidase activation was found to be associated with the translocation of p47(phox) to the membrane. In isolated and pressurized small coronary arteries, N-vanillylnonanamide, apocynin, or uric acid, a peroxynitrite scavenger, largely restored the inhibitory effects of ceramide on bradykinin- and A-23187-induced vasorelaxation. With the use of nitrotyrosine as a marker, C(2)-ceramide was found to increase peroxynitrite in small coronary arteries, which could be blocked by uric acid. We conclude that NADPH oxidase-mediated superoxide production and subsequent peroxynitrite formation mediate ceramide-induced endothelial dysfunction in small coronary arteries.
Author List
Zhang DX, Zou AP, Li PLAuthor
David X. Zhang MD, PhD Associate Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBiological Transport
Cattle
Cells, Cultured
Ceramides
Coronary Vessels
Endothelium, Vascular
Enzyme Activation
Isoenzymes
NADPH Oxidases
Peroxynitrous Acid
Phosphoproteins
Reactive Oxygen Species
Tyrosine
