ETR对人食管下括约肌收缩调节

目的：通过测定内皮素受体（ ETR）与ETR激动剂和拮抗剂结合后人食管下括约肌的收缩变化，研究ETR对食管下括约肌的收缩调节作用。方法于食管癌患者的食管胃结合部取下套索纤维和钩状纤维肌条组织（属于食管下括约肌）。再于浸润有肌条组织的浴槽内先加入ET?1，再分别加入ETR 2种受体亚型（ ETA、 ETB）的受体拮抗剂（ BQ?123、 BQ?788），同时测定不同给药浓度下肌张力的变化曲线。结果 ET?1对2种肌条均有收缩作用。 ETA和ETB均参与了ET?1引起的食管下括约肌的收缩，而且ETA激动后引起的收缩作用要显著强于ETB。每个受体亚型在不同肌条上引起的收缩作用无差别。结论 ETR均可以引起食管下括约肌收缩。 ETA亚型对ETR引起的收缩起主要作用，可能是调节人食管下括约肌的张力变化的重要受体。

Contraction regulation of human lower esophageal sphincter by ETRs

Objective To identify the contraction regulation of human lower esophageal sphincter ( LES) by iden?tifying the combination of ligand and ETRs. Methods The sling and clasp circular muscle strips were obtained from LES, which was resected from esophageal cancer patients. ET?1 was added into bath, which contained mus?cle strip. Then, antagonist BQ?123 and BQ?788 were added into bath respectively. At the meantime, the varia?tion of tension curve under different cumulative concentration changes were recorded. Results ET?1 could induce all muscle strip to contract. ETA and ETB were both involved in the LES contraction, which was induced by ET?1. And the effects of ETA were much stronger than that of ETB. But each isoform effect of ET had no differ?ence between different muscle strips. Conclusion ETR can be found in human LES. ETA probably plays an im?portant role in contractile regulation of human LES.