Hydrogen sulfide mediates hypoxia-induced relaxation of trout urinary bladder smooth muscle

• DOI: 10.1242/jeb.02376
• Publication Date: 2006-08-03T17:57:49Z
• Authors: Ryan A. Dombkowski; Meredith M. Doellman; Sally K. Head; Kenneth R. Olson
• Keywords: Apamin; Sodium hydrosulfide; Myograph; Hypoxia

Hydrogen sulfide (H2S) is a recently identified gasotransmitter that may mediate hypoxic responses in vascular smooth muscle. H2S also appears to be signaling molecule mammalian non-vascular muscle, but its existence and function non-mammalian muscle have not been examined. In the present study we examined production physiological effects urinary bladder from steelhead rainbow trout (Oncorhynchus mykiss) evaluated relationship between hypoxia. was produced by bladders, sensitive inhibitors of cystathionine beta-synthase gamma-lyase. dose-dependent relaxation unstimulated carbachol pre-contracted bladders inhibited spontaneous contractions. Bladders with 80 mmol l(-1) KCl were less than contracted either KC2H3O2 (KAc) or carbachol, suggesting some are mediated through an ion channel. However, affected potassium channel inhibitors, apamin, charybdotoxin, 4-aminopyridine, glybenclamide, chloride channel/exchange 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt, tamoxifen presence absence extracellular HCO3-. Inhibitors neuronal mechanisms, tetrodotoxin, strychnine N-vanillylnonanamide likewise ineffective. Hypoxia (aeration N2) relaxed competitive for relaxation, it equally KCl, unaffected blockade synthesis relaxation. These experiments suggest phylogenetically ancient serves as oxygen sensor/transducer, mediating