Faculty Collaboration Database

Pulmonary arterial endothelial cells affect the redox status of coenzyme Q0. Free Radic Biol Med 2003 Apr 01;34(7):892-907

Date

03/26/2003

Pubmed ID

12654478

DOI

10.1016/s0891-5849(03)00025-x

Scopus ID

2-s2.0-0037376429 (requires institutional sign-in at Scopus site)   17 Citations

Abstract

The pulmonary endothelium is capable of reducing certain redox-active compounds as they pass from the systemic venous to the arterial circulation. This may have important consequences with regard to the pulmonary and systemic disposition and biochemistry of these compounds. Because quinones comprise an important class of redox-active compounds with a range of physiological, toxicological, and pharmacological activities, the objective of the present study was to determine the fate of a model quinone, coenzyme Q0 (Q), added to the extracellular medium surrounding pulmonary arterial endothelial cells in culture, with particular attention to the effect of the cells on the redox status of Q in the medium. Spectrophotometry, electron paramagnetic resonance (EPR), and high-performance liquid chromatography (HPLC) demonstrated that, when the oxidized form Q is added to the medium surrounding the cells, it is rapidly converted to its quinol form (QH2) with a small concentration of semiquinone (Q*-) also detectable. The isolation of cell plasma membrane proteins revealed an NADH-Q oxidoreductase located on the outer plasma membrane surface, which apparently participates in the reduction process. In addition, once formed the QH2 undergoes a cyanide-sensitive oxidation by the cells. Thus, the actual rate of Q reduction by the cells is greater than the net QH2 output from the cells.

Author List

Audi SH, Zhao H, Bongard RD, Hogg N, Kettenhofen NJ, Kalyanaraman B, Dawson CA, Merker MP

Authors

Said Audi PhD Professor in the Biomedical Engineering department at Marquette University
Neil Hogg PhD Associate Dean, Professor in the Biophysics department at Medical College of Wisconsin
Balaraman Kalyanaraman PhD Professor in the Biophysics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Arteries
Biotin
Biotinylation
Cattle
Cell Membrane
Cells, Cultured
Chromatography, High Pressure Liquid
Dose-Response Relationship, Drug
Electron Spin Resonance Spectroscopy
Electrons
Endothelium, Vascular
Free Radicals
Lung
Models, Chemical
NADP
Oxidation-Reduction
Time Factors
Ubiquinone