Effect of otilonium bromide and ibodutant on the internalization of the NK2 receptor in human colon

摘要: Background  The present aim was to study the modulation of NK2 receptor internalization by two compounds, spasmolytic otilonium bromide (OB) endowed with antagonistic properties and selective antagonist ibodutant. Methods  Full-thickness human colonic segments were incubated in presence OB (0.1–10 μmol L−1) or ibodutant (0.001–0.1 μmol L−1), without agonist [βAla8]NKA(4–10) then fixed 4% paraformaldehyde. Cryosections processed for immunohistochemical revelation. Quantitative analysis evaluated number smooth muscle cells that had internalized receptor. Key Results  Immuno-histochemistry revealed basal condition, about 23% total cells. exposure induced more than 77% Previous both ibodutant, either alone agonist, concentration-dependently reduced receptor. Conclusions & Inferences  Both antagonize colon. As receptors are predominant mediating spasmogenic activity tachykinins on enteric muscle, we hypothesize found should play a specific therapeutic role gut diseases characterized hypermotility.