title: Responses of human sling and clasp fibers to cholecystokinin (CCK) and gastrin through CCK receptors.
abstract: OBJECTIVE
  Cholecystokinin (CCK) and gastrin exert their influences via CCK receptors. This research was conducted to look at the responses of the sling and clasp fibers forming the human lower esophageal sphincter (LES) to CCK and gastrin, and the role of CCK receptors in the responses.
  
  
  METHODS
  Muscle strips of sling and clasp fibers from the LES were obtained from patients undergoing subtotal esophagectomy. Isometric tension responses of the strips to CCK-8 and gastrin-17 were studied, and the maximum effect (E(max)) for each agonist was derived. CCK-A receptor antagonist, CR1409 and CCK-B antagonist, CR2945 were applied to sling and clasp fibers and their pK(B) values were calculated.
  
  
  RESULTS
  Sling fibers produced significant contractions following exposure to CCK-8 and gastrin-17, while clasp fibers had less responses to the two agents. CR1409 and CR2945 inhibited responses of sling to CCK-8 in a concentration-dependent fashion. The inhibition effects of the two antagonists on clasp fibers were not measurable because there was a mild contraction of the fiber in response to CCK-8.
  
  
  CONCLUSIONS
  The contractions generated by sling fibers following exposure to CCK and gastrin are greater than that produced by clasp fibers. CCK-A receptors are more important for the generation of contractions by the sling fibers, whereas both CCK-A and CCK-B receptors are involved in the functional regulation of the clasp fibers. [Corrections added after online publication 28 April 2008: in the Background and Aims section of the preceding abstract, all instances of 'CKK' were corrected to 'CCK'. In the final sentence of the abstract 'CCKA'was corrected to 'CCK-A'. In the article title '(CKK)' was corrected to '(CCK)'.].
authors.affiliation: Department of Thoracic Surgery, Fourth Hospital, Hebei Medical University, Shijiazhuang, China. liujf@heinfo.net
authors.forename: Jun-Feng
authors.initials: JF
authors.lastname: Liu
authors.forename: Li-Ping
authors.initials: LP
authors.lastname: Gao
authors.forename: Shi-Wang
authors.initials: SW
authors.lastname: Wen
authors.forename: Hui-Lai
authors.initials: HL
authors.lastname: Lu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Sun
authors.forename: Shao-Wei
authors.initials: SW
authors.lastname: Zhang
authors.forename: Qi-Zhang
authors.initials: QZ
authors.lastname: Wang
mesh_terms: D000328:Adult; D001569:Benzodiazepines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D049630:Esophageal Sphincter, Lower / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000601:surgery; D016629:Esophagectomy; D005260:Female; D005755:Gastrins / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D032389:Myocytes, Smooth Muscle / Q000187:drug effects; D011377:Proglumide / Q000031:analogs & derivatives / Q000494:pharmacology; D043886:Receptor, Cholecystokinin A / Q000037:antagonists & inhibitors / Q000378:metabolism*; D043887:Receptor, Cholecystokinin B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012844:Sincalide / Q000378:metabolism*
chemical_list: C116183:CR 2945; D005755:Gastrins; D043886:Receptor, Cholecystokinin A; D043887:Receptor, Cholecystokinin B; D001569:Benzodiazepines; C013550:gastrin 17; D011377:Proglumide; C048181:lorglumide; D012844:Sincalide