title: The effects of hydrogen sulfide on electrical field stimulation-induced neurogenic contractile responses in isolated rabbit lower esophageal sphincter: Contribution of nitrergic and non-adrenergic non-cholinergic transmission.
abstract: BACKGROUND
  Hydrogen sulfide (H2S) is a gaseous signaling molecule that, similar to nitric oxide (NO), plays an important role as an inhibitor neurotransmitter in the digestive tract. This study aimed to investigate the effect of H2S and to identify neurogenic contraction responses dependent on the electrical field stimulation (EFS) in the isolated lower esophageal sphincters of rabbits.
  
  
  METHODS
  An isolated lower esophageal sphincter was placed in an organ bath system and mechanical responses were recorded using a force transducer. The nerve-evoked contractile responses were obtained by EFS. The contractile responses were obtained as biphasic "on" and "off" phases seen at the beginning and end of EFS, respectively.
  
  
  RESULTS
  Sodium hydrogen sulfide (NaHS) reduced the EFS-mediated "off" phase and the EFS-mediated non-adrenergic non-cholinergic (NANC) "off" phase. NaHS reduced the EFS-mediated "on" phase as well. l-Cysteine ​​reduced the EFS-mediated "off" phase and the EFS-mediated NANC "off" phase. l-Propargylglycine (PAG) did not affect the EFS-mediated "off" phase or the EFS-mediated NANC "off" phase. NaHS, l-cysteine, and PAG reduced the EFS-mediated, NO-independent "off" phase. The effect of NaHS in all of the experiments returned in time. Also, NaHS caused significant relaxation of 80-mM KCl-Krebs solution induced-contractions, while l-cysteine ​​and PAG did not cause a significant relaxation.
  
  
  CONCLUSIONS
  These findings suggest that H2S has an inhibitory effect on the lower esophageal sphincter muscle. While the effect of H2S on EFS-mediated responses disappeared in time, the effect of H2S sustained the KCl-Krebs solution-induced contractions. This shows that H2S may have an effect on neurotransmission at the nerve terminal.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, Yildirim Beyazit University, Ankara, Turkey.
authors.forename: Halil
authors.initials: H
authors.lastname: Kara
authors.affiliation: Turkish Medicines and Medical Devices Agency, Ministry of Health, Ankara, Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Isli
authors.affiliation: Department of Medical Pharmacology, Faculty of Medicine, Gazi University, Ankara, Turkey. Electronic address: gokcesevimozturk@yahoo.com.
authors.forename: Gokce Sevim
authors.initials: GS
authors.lastname: Ozturk Fincan
authors.affiliation: University of Health Sciences, Ankara Numune Education and Research Hospital, Ankara, Turkey.
authors.forename: Seniz
authors.initials: S
authors.lastname: Yildirim
authors.affiliation: Member of Turkish Academy of Science, Turkey.
authors.forename: Sevim
authors.initials: S
authors.lastname: Ercan
authors.affiliation: Department of Medical Pharmacology, Faculty of Medicine, Gazi University, Ankara, Turkey.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Sarioglu
mesh_terms: D059331:Adrenergic Neurons; D000818:Animals; D059329:Cholinergic Neurons; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation / Q000379:methods; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000378:metabolism; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D026602:Nitrergic Neurons / Q000187:drug effects* / Q000502:physiology; D009924:Organ Culture Techniques; D011817:Rabbits; D009435:Synaptic Transmission / Q000187:drug effects / Q000502:physiology
chemical_list: D006862:Hydrogen Sulfide
keywords: Electrical field stimulation; Hydrogen sulfide; Lower esophageal sphincter