title: H2 S modulates duodenal motility in male rats via activating TRPV1 and K(ATP) channels.
abstract: OBJECTIVE
  H2 S induces vasodilatation by opening KATP channels but it may also affect other ion channels. The aim of this study was to investigate the effect of H2 S on intestinal motility in rats and its underlying mechanism.
  
  
  METHODS
  The tension of intestinal muscle strips, afferent firing of intestinal mesenteric nerves, length of duodenal smooth muscle cells and whole-cell membrane potential of dorsal root ganglion (DRG) neurons were monitored. H2 S-producing enzymes were located by immunofluorescence staining.
  
  
  RESULTS
  NaHS exerted early transient excitation and late long-lasting inhibition on the intestinal contraction. The excitation was attenuated by TRPV1 antagonists capsazepine, A784168, SB-366791 and NK1 receptor antagonist L703606, while the inhibition was attenuated by glibenclamide. NaHS increased duodenal afferent nerve firing and depolarized DRG neurons. These effects were reduced by capsazepine and A784168. NaHS relaxed isolated duodenal smooth muscle cells. The KATP channels were expressed in smooth muscle cells. Cystathionine β-synthase and cystathionine γ-lyase were expressed in rat duodenal myenteric neurons. L-cysteine and S-adenosyl-L-methionine increased the contraction of duodenal muscle strips, an effect attenuated by capsazepine and L703606.
  
  
  CONCLUSIONS
  NaHS induces biphasic effects on intestinal motility in rats while endogenous H2 S only exerts an excitatory effect. This transient excitatory effect might be mediated by activation of TRPV1 channels in sensory nerve terminals with the consequent release of substance P. The long-lasting inhibitory effect might be mediated by activation of KATP channels in the smooth muscle cells. These findings reveal a novel mechanism for the excitatory effect of H2 S on gastrointestinal motility.
authors.affiliation: Department of Physiology, Shandong University School of Medicine, Jinan, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Lu
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Liping
authors.initials: L
authors.lastname: Gong
authors.forename: Xiaomeng
authors.initials: X
authors.lastname: Xu
authors.forename: Ting
authors.initials: T
authors.lastname: Han
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Ye
authors.forename: Tongtong
authors.initials: T
authors.lastname: Che
authors.forename: Yan
authors.initials: Y
authors.lastname: Luo
authors.forename: Jingxin
authors.initials: J
authors.lastname: Li
authors.forename: Renzhi
authors.initials: R
authors.lastname: Zhan
authors.forename: Wei
authors.initials: W
authors.lastname: Yao
authors.forename: Kejing
authors.initials: K
authors.lastname: Liu
authors.forename: Shuang
authors.initials: S
authors.lastname: Cui
authors.forename: Chuanyong
authors.initials: C
authors.lastname: Liu
mesh_terms: D000818:Animals; D004386:Duodenum / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D005727:Ganglia, Spinal / Q000166:cytology; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar
chemical_list: D006862:Hydrogen Sulfide
keywords: H2S; KATP; TRPV1; duodenum; motility