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URBAN PARTICLE-INDUCED PULMONARY ARTERY CONSTRUCTION IS MEDIATED BY SUPEROXIDE PRODUCTION
Citation:
Carter, J, L. A. Dailey, Huang, YuhChin T, AND Z. Li. URBAN PARTICLE-INDUCED PULMONARY ARTERY CONSTRUCTION IS MEDIATED BY SUPEROXIDE PRODUCTION. Presented at Oxygen Society Meeting, San Antonio, TX, November 20-24, 2002.
Description:
URBAN PARTICLE-INDUCED PULMONARY ARTERY CONSTRICTION IS MEDIATED BY SUPEROXIDE PRODUCTION.Jacqueline D. Carter, Zhuowei Li, Lisa A. Dailey, Yuh-Chin T. Huang. CEMALB, University of North Carolina, and ORD, US EPA, Chapel Hill, North Carolina.
Exposure to particulate matter (PM) is associated with cardiovascular morbidity and mortality, but the mechanisms for such adverse events are unclear. We hypothesized that particles from different sources, which contain different metal constituents, will have different potency for inducing pulmonary vasoconstriction. We investigated the vasoconstrictive property of two different PM, diesel (DP) and urban particle-St. Louis (UP). In rat pulmonary artery ring system, both DP and UP produced dose-dependent vasoconstriction (1 to 100 mg/ml of particles). Based on the same mass, UP produced significantly greater vasoconstriction than DP. The UP-induced vasoconstriction approached that produced by 1 mM of phenylephrine at concentrations greater than 10 mg/ml. Vasoconstriction induced by UP could be completely inhibited by SOD (100 U/ml) and diphenyliodonium (4 mM), a flavoprotein inhibitor. UP-treated vascular ring also had impaired acetylcholine-dependent vasorelaxation. Treatment of cultured human pulmonary endothelial cells with UP produced increased fluorescence of dihydroethidium. Of the metal constituents associated with UP, Cu and V, but not Fe, Ni or Zn, produced pulmonary vasoconstriction in a dose-dependent manner. The results indicate that UP-induced pulmonary vasoconstriction was mediated by endothelium-derived oxidants produced by vascular NADPH oxidoreductase, and was in part related to its Cu and V content. (This abstract does not reflect EPA policy).