Intracellular redox status affects transplasma membrane electron transport in pulmonary arterial endothelial cells. Am J Physiol Lung Cell Mol Physiol 2002 Jan;282(1):L36-43
Date
12/14/2001Pubmed ID
11741813DOI
10.1152/ajplung.00283.2001Scopus ID
2-s2.0-0036082644 (requires institutional sign-in at Scopus site) 57 CitationsAbstract
Pulmonary arterial endothelial cells possess transplasma membrane electron transport (TPMET) systems that transfer intracellular reducing equivalents to extracellular electron acceptors. As one aspect of determining cellular mechanisms involved in one such TPMET system in pulmonary arterial endothelial cells in culture, glycolysis was inhibited by treatment with iodoacetate (IOA) or by replacing the glucose in the cell medium with 2-deoxy-D-glucose (2-DG). TPMET activity was measured as the rate of reduction of the extracellular electron acceptor polymer toluidine blue O polyacrylamide. Intracellular concentrations of NADH, NAD(+), NADPH, and NADP(+) were determined by high-performance liquid chromatography of KOH cell extracts. IOA decreased TPMET activity to 47% of control activity concomitant with a decrease in the NADH/NAD(+) ratio to 34% of the control level, without a significant change in the NADPH/NADP(+) ratio. 2-DG decreased TPMET activity to 53% of control and decreased both NADH/NAD(+) and NADPH/NADP(+) ratios to 51% and 55%, respectively, of control levels. When lactate was included in the medium along with the inhibitors, the effects of IOA and 2-DG on both TPMET activity and the NADPH/NADP(+) ratios were prevented. The results suggest that cellular redox status is a determinant of pulmonary arterial endothelial cell TPMET activity, with TPMET activity more highly correlated with the poise of the NADH/NAD(+) redox pair.
Author List
Merker MP, Bongard RD, Kettenhofen NJ, Okamoto Y, Dawson CAMESH terms used to index this publication - Major topics in bold
AnimalsCattle
Cell Membrane
Cells, Cultured
Deoxyglucose
Electron Transport
Endothelium, Vascular
Intracellular Membranes
Iodoacetates
Lactic Acid
NAD
Oxidation-Reduction
Pulmonary Artery
