title: Unexpected insensitivity of the cholinergic motor responses to morphine in the human small intestine.
abstract: OBJECTIVE
  morphine is known to inhibit cholinergic contractions of the guinea pig small intestine. This has been compared to the human small intestinal innervated longitudinal muscle in the current study.
  
  
  METHODS
  cholinergic primary contractions of human small intestinal longitudinal strips were evoked by electrical field stimulation (EFS; 0.5- 5 Hz in the presence of purinergic and nitrergic blockers or 5 Hz without pretreatment) and recorded isotonically in organ bath experiments. Guinea pig small intestinal segments were also studied.
  
  
  CONCLUSIONS
  neurogenic cholinergic contractions of human preparations were unaffected by morphine (1, 2 or 10 micromol/l). Longitudinal contractions of the guinea pig ileum were concentration-dependently suppressed by morphine (0.1-10 micromol/l). It is concluded that myenteric neurons supplying the longitudinal muscle of the human small intestine are much less sensitive to morphine than those of the guinea pig.
authors.affiliation: Department of Pharmacology and Pharmacotherapy, University Medical School of Pécs, Hungary.
authors.forename: Rita
authors.initials: R
authors.lastname: Benko
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Molnár
authors.forename: Dániel
authors.initials: D
authors.lastname: Nemes
authors.forename: András
authors.initials: A
authors.lastname: Dékány
authors.forename: Dezsö
authors.initials: D
authors.lastname: Kelemen
authors.forename: Lászlo
authors.initials: L
authors.lastname: Illényi
authors.forename: Lászlo
authors.initials: L
authors.lastname: Cseke
authors.forename: András
authors.initials: A
authors.lastname: Papp
authors.forename: Gábor
authors.initials: G
authors.lastname: Varga
authors.forename: Loránd
authors.initials: L
authors.lastname: Bartho
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004558:Electric Stimulation; D006168:Guinea Pigs; D006801:Humans; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000187:drug effects* / Q000294:innervation; D009020:Morphine / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D011950:Receptors, Cholinergic / Q000378:metabolism*
chemical_list: D000701:Analgesics, Opioid; D011950:Receptors, Cholinergic; D009020:Morphine