Role of G(s) proteins in hypoxic constriction of sheep pulmonary artery rings.
The introduction of hypoxia is well known to cause contraction of pulmonary artery rings in vitro. Despite intensive studies, the cellular mechanisms of hypoxic pulmonary vasoconstriction are still not well defined. In this study, we aimed to determine the contribution of G(S) proteins in hypoxia-induced vasoconstriction in large-diameter sheep pulmonary arteries using cholera toxin (CT). Hypoxia caused further contractions in serotonin but not in NaF-precontracted pulmonary artery rings. However, hypoxic vasoconstriction due to lowering of pO(2) from 97 to 5 mm Hg was totally abolished by preincubation with CT in serotonin-precontracted arteries. These preliminary results indicate that signal transduction mediated by G(s) proteins may be an important mechanism in the hypoxic vasoconstriction of isolated pulmonary arteries of sheep.
Uzun
Ozge
O
Department of Pharmacology, Abant Izzet Baysal University, Faculty of Medicine, Düzce, Turkey.
Demiryürek
A Tuncay
AT
Kanzik
Ilker
I
D000818:Animals; D002772:Cholera Toxin / Q000494:pharmacology; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000502:physiology*; D000860:Hypoxia / Q000503:physiopathology*; D066298:In Vitro Techniques; D011651:Pulmonary Artery / Q000187:drug effects / Q000502:physiology*; D012701:Serotonin / Q000494:pharmacology; D012756:Sheep; D012969:Sodium Fluoride / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D012701:Serotonin; D012969:Sodium Fluoride; D002772:Cholera Toxin; D019205:GTP-Binding Protein alpha Subunits, Gs