Hydrogen sulphide-induced relaxation of porcine peripheral bronchioles

摘要: Background and Purpose Hydrogen sulphide (H2S) is an endogenous gasotransmitter. Although it has been shown to elicit responses in vascular other smooth muscle preparations, a role for endogenously produced H2S mediating airway tone yet be demonstrated. Therefore, the aim of this study was determine whether within airways functional effect on tone. Experimental Approach Small peripheral (<5 mm diameter) from porcine lungs were set up isolated tissue baths, pre-contracted with muscarinic agonist carbachol, then exposed either donor sodium hydrosulphide (NaHS), or precursor L-cysteine. production L-cysteine 3-mercaptopyruvate homogenates measured by methylene blue assay. Expression H2S-synthesizing enzymes cystathionine β-synthase (CBS), γ lyase (CSE) sulphurtransferase (3-MST) Western blotting. Key Results NaHS caused large relaxation airways, which inhibited partially pre-contraction KCl exposure tetraethylammonium, but not glibenclamide, paxilline 4-aminopyridine. also CBS inhibitor aminooxyacetic acid. Tissue vitro showed significant H2S. blotting demonstrated immunoreactivity CBS, CSE 3-MST airways. Conclusions Implications These data demonstrate that can causing relaxation. The mechanism depends, part, K+ channel activity.