title: Inhibition of p38 MAPK reverses hypoxia-induced pulmonary artery endothelial dysfunction.
abstract: Hypoxia-induced endothelial dysfunction plays a crucial role in the pathogenesis of hypoxic pulmonary hypertension. p38 MAPK expression is increased in the pulmonary artery following hypoxic exposure. Recent evidence suggests that increased p38 MAPK activity is associated with endothelial dysfunction. However, the role of p38 MAPK activation in pulmonary artery endothelial dysfunction is not known. Sprague-Dawley rats were exposed to 2 wk hypobaric hypoxia, which resulted in the development of pulmonary hypertension and vascular remodeling. Endothelium-dependent relaxation of intrapulmonary vessels from hypoxic animals was impaired due to a reduced nitric oxide (NO) generation. This was despite increased endothelial NO synthase immunostaining and protein expression. Hypoxia exposure increased superoxide generation and p38 MAPK expression. The inhibition of p38 MAPK restored endothelium-dependent relaxation, increased bioavailable NO, and reduced superoxide production. In conclusion, the pharmacological inhibition of p38 MAPK was effective in increasing NO generation, reducing superoxide burden, and restoring hypoxia-induced endothelial dysfunction in rats with hypoxia-induced pulmonary hypertension. p38 MAPK may be a novel target for the treatment of pulmonary hypertension.
authors.affiliation: Scottish Pulmonary Vascular Unit, Level 8, Western Infirmary, Dumbarton Rd., Glasgow G11 6NT, UK.
authors.forename: Roshan P
authors.initials: RP
authors.lastname: Weerackody
authors.forename: David J
authors.initials: DJ
authors.lastname: Welsh
authors.forename: Roger M
authors.initials: RM
authors.lastname: Wadsworth
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Peacock
mesh_terms: D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000201:enzymology / Q000209:etiology / Q000503:physiopathology; D000860:Hypoxia / Q000150:complications* / Q000188:drug therapy / Q000201:enzymology / Q000503:physiopathology; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000187:drug effects* / Q000201:enzymology / Q000503:physiopathology; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013481:Superoxides / Q000378:metabolism; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism
chemical_list: D000959:Antihypertensive Agents; D007093:Imidazoles; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D014665:Vasodilator Agents; D013481:Superoxides; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D048051:p38 Mitogen-Activated Protein Kinases; C093642:SB 203580