Role of mitochondrial electron transport complex I in coenzyme Q1 reduction by intact pulmonary arterial endothelial cells and the effect of hyperoxia

Abstract

RD. Role of mitochondrial electron transport complex I in coen-zyme Q1 reduction by intact pulmonary arterial endothelial cells and the effect of hyperoxia. Am J Physiol Lung Cell Mol Phys-iol 293: L809–L819, 2007. First published June 29, 2007; doi:10.1152/ajplung.00448.2006.—The objective was to determine the impact of intact normoxic and hyperoxia-exposed (95 % O2 for 48 h) bovine pulmonary arterial endothelial cells in culture on the redox status of the coenzyme Q10 homolog coenzyme Q1 (CoQ1). When CoQ1 (50 M) was incubated with the cells for 30 min, its concentration in the medium decreased over time, reaching a lower level for normoxic than hyperoxia-exposed cells. The decreases in CoQ1 concentration were associated with generation of CoQ1 hydro-quinone (CoQ1H2), wherein 3.4 times more CoQ1H2 was produced in the normoxic than hyperoxia-exposed cell medium (8.2 0.3 and 2.4 0.4 M, means SE, respectively) after 30 min. The maximu