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Krueger, D.; Foerster, M.; Mueller, K.; Zeller, F.; Slotta-Huspenina, J.; Donovan, J.; Grundy, D.; Schemann, M. 
Signaling mechanisms involved in the intestinal pro-secretory actions of hydrogen sulfide. 
BACKGROUND: H(2) S actions in the gut involve neural activation. This study aimed to reveal the signaling mechanisms responsible for the pro-secretory effect of H(2) S by using TRPV1 and unselective TRP blockers and inhibitors of other signaling cascades hitherto described to be targeted by H(2) S elsewhere. METHODS: Ussing chamber voltage clamp technique was used to study actions of the H(2) S donor NaHS on secretion in guinea-pig and human colon. NaHS effects on guinea-pig primary afferents were also evaluated. KEY RESULTS: NaHS evoked secretion was significantly reduced in guinea-pig and human tissue by the selective TRPV1 blockers capsazepine, AMG9801, SB705498, BCTC; LY294002 (Phosphatidylinositol-3 kinase (PI3K) inhibitor), SKF96365 (store operated calcium channel blocker), 2-APB (inositol triphosphate blocker), and atropine but not by HC030031 (TRPA1 blocker) or L- and T-type calcium channel antagonists. Actions of TRPV1 antagonists suggested non-competitive inhibition at multiple sites. In guinea-pig colon, Gd(3+) and La(3+) (unselective TRP blockers) had no effects while ruthenium red reduced NaHS effects; in human colon Gd(3+) attenuated NaHS response. NaHS response was inhibited by neurokinin-1 and -3 receptor blockers in guinea-pig and neurokinin-1 and -2 receptor blockade in human tissue. There was cross-desensitization between NaHS and capsaicin responses. NaHS induced capsazepine and LY294002 sensitive afferent discharge. CONCLUSIONS & INFERENCES: H(2) S evokes mucosal secretion by targeting TRPV1 expressing afferent nerves which activate cholinergic secretomotor neurons via release of substance P acting in a species dependent manner on neurokinin-1, -2 or -3 receptors. Besides TRPV1 signaling H(2) S may target intracellular calcium dependent pathways and PI3K. 
Animals, Humans, Guinea Pigs, In Vitro Techniques, Aged, Calcium Channel Blockers/pharmacology, Female, Male, Middle Aged, Calcium/physiology, Diffusion Chambers, Culture, Hydrogen Sulfide/*pharmacology, Intestines/*drug effects/innervation, Jejunum/drug effects/innervation/secretion, Neurons, Afferent/drug effects, Neurotransmitter Agents/physiology, Signal Transduction/*drug effects/physiology, Substance P/physiology, Sulfides/pharmacology, TRPV Cation Channels/antagonists & inhibitors/physiol...    »
Journal title:
Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society 
Journal volume:
Journal issue:
Pages contribution:
1224--31, e319--320 
1365-2982 1350-1925