Investigation of the Contribution of Potassium Channels in the Relaxing Effect of Hydrogen Sulfide in Isolated Rabbit Lower Esophagus Sphincter

Koç A., Koç D. S., Aşkın C. İ., Kara H., Öztürk Fincan G. S., Özger İlhan S., ...Daha Fazla

19th World Congress of Basic & Clinical Pharmacology 2023, Glasgow, İngiltere, 2 - 07 Temmuz 2023, ss.1124-1227

  • Yayın Türü: Bildiri / Özet Bildiri
  • Basıldığı Şehir: Glasgow
  • Basıldığı Ülke: İngiltere
  • Sayfa Sayıları: ss.1124-1227
  • Gazi Üniversitesi Adresli: Evet

Özet

Introduction Hydrogen sulfide (H2S) is a gaseous signaling molecule with an inhibitory effect in the gastrointestinal system. We previously demonstrated the relaxant effect of NaHS and L-Cysteine and the role of Glibenclamide and TEA on EFS-mediated Nitric oxide (NO)-dependent and -independent contractile responses in rabbit lower esophageal sphincter (LES) [1]. The present study addressed the question of whether potassium channels and NO were involved in the relaxant effects of H2S in rabbit LES.

Method LES was obtained from thirty-six New Zealand Albino male adult rabbits following euthanasia with ketamine/xylazine (50 mg/kg/5mg/kg, IV). LES was carefully dissected out and two strips were obtained from each animal. For isometric tension studies, strips were mounted in a 20-ml organ bath containing Krebs solution, which was bubbled with 95% O2 and 5% CO2 and maintained at 37◦C with a pH of 7.4. EFS was applied 16 Hz., 60 V, 1 ms., 10 s. A tension of 1 g was applied, and tissues were allowed to equilibrate for 1 hour. Effective concentrations of H2S were based on our preliminary studies [2]. Our experimental protocols are presented inTable 1. Results NaHS, L-Cysteine, PAG, and AOAA significantly reduced EFS-mediated NO-dependent and -independent contractile responses. The relaxation responses significantly varied between the NO-dependent and NO-independent groups (Table 1,2,3,4). NaHS caused statistically significant relaxation meanwhile L-Cysteine and PAG and AOAA did not induce significant relaxation in tissues contracted with KCl and Ca2+. Statistical comparison between the groups was performed by the Kruskal–Wallis test followed by Mann–Whitney U test. Conclusions These results suggested that the relaxing effects of hydrogen sulfide on EFS-mediated cholinergic contractile responses may be mediated by nitric oxide and potassium channels, specifically KV channels in the lower esophageal sphincter.