Oxidant stress regulates basal endothelin-1 production by cultured rat pulmonary endothelial cells.
Endothelin-1 (ET-1) is a pluripotent mediator that modulates vascular tone and influences the inflammatory response. Patients with inflammatory lung disorders frequently have elevated circulating ET-1 levels. Because these pathophysiological conditions generate reactive oxygen species that can regulate gene expression, we investigated whether the level of oxidant stress influences ET-1 production in cultured rat pulmonary arterial endothelial cells (RPAEC). Treatment with the antioxidant 1,3-dimethyl-2-thiourea (10 mM) or the iron chelator deferoxamine (1.8 microM) doubles basal ET-1 release. Conversely, exposing cells to H2O2 generated by glucose and glucose oxidase (0.1-10 mU/ml) for 4 h causes a concentration-dependent decrease in ET-1 release. This effect occurs at concentrations of glucose oxidase that do not affect [3H]leucine incorporation or specific 51Cr release from RPAEC. Catalase prevents the decrease in ET-1 synthesis caused by glucose and glucose oxidase. Glucose and glucose oxidase decrease not only ET-1 generation but also ET-1 mRNA as assessed by semiquantitative polymerase chain reaction. Our results indicate that changes in oxidative stress can either up- or downregulate basal ET-1 generation by cultured pulmonary endothelial cells.
Michael
J R
JR
Department of Medicine, Veterans Affairs Medical Center, University of Utah School of Medicine, Salt Lake City 84132, USA.
Markewitz
B A
BA
Kohan
D E
DE
D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002478:Cells, Cultured; D003676:Deferoxamine / Q000494:pharmacology; D019332:Endothelin-1 / Q000096:biosynthesis*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D016166:Free Radical Scavengers / Q000494:pharmacology; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism; D005949:Glucose Oxidase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007930:Leucine / Q000378:metabolism; D018384:Oxidative Stress; D016133:Polymerase Chain Reaction; D011651:Pulmonary Artery; D051381:Rats; D013890:Thiourea / Q000031:analogs & derivatives / Q000494:pharmacology
D000975:Antioxidants; D019332:Endothelin-1; D016166:Free Radical Scavengers; C038983:1,3-dimethylthiourea; D006861:Hydrogen Peroxide; D005949:Glucose Oxidase; D007930:Leucine; D013890:Thiourea; D005947:Glucose; D003676:Deferoxamine