title: Mechanism of action of Trolox on duodenal contractility.
abstract: Trolox is a hydrophilic analogue of vitamin E. The aim of this work was to study the mechanism of action of Trolox on rabbit duodenal spontaneous motility and contractility. The duodenal contractility studies in vitro were carried out in an organ bath. Trolox (12 mM) reduced the amplitude and frequency of spontaneous contractions and the acetylcholine-induced contractions in the longitudinal and circular smooth muscle of rabbit duodenum. Quinine reverted the Trolox-induced (12 mM) reduction on the amplitude and frequency of spontaneous contractions in the longitudinal and circular muscle. Charibdotoxin and glibenclamide reverted only the amplitude of spontaneous contractions in circular muscle of the duodenum. The decrease of ACh-induced contractions evoked by Trolox 12 mM in the longitudinal and circular smooth muscle of the duodenum was antagonized by quinine in longitudinal and circular muscle and by Bay K8644, 1H-[1,2,4]oxadiazolo [4, 3-α]quinoxalin-1-one (ODQ) and nimesulide in circular muscle. We conclude that in the decrease of duodenal contractility induced by Trolox participate K(+) and Ca(2+) channels, adenylyl cyclase, guanylyl cyclase and cyclooxygenase-2.
authors.affiliation: Departamento de Farmacologia y Fisiologia (Fisiologia), Facultad de Veterinaria, Universidad de Zaragoza, Zaragoza, Spain. dmurillo@unizar.es.
authors.forename: D S
authors.initials: DS
authors.lastname: Fagundes
authors.forename: L
authors.initials: L
authors.lastname: Grasa
authors.forename: S
authors.initials: S
authors.lastname: Gonzalo
authors.forename: F
authors.initials: F
authors.lastname: Martinez de Salinas
authors.forename: M P
authors.initials: MP
authors.lastname: Arruebo
authors.forename: M A
authors.initials: MA
authors.lastname: Plaza
authors.forename: M D
authors.initials: MD
authors.lastname: Murillo
mesh_terms: D000262:Adenylyl Cyclases / Q000502:physiology; D000818:Animals; D020746:Calcium Channels, L-Type / Q000502:physiology; D002839:Chromans / Q000494:pharmacology*; D051546:Cyclooxygenase 2 / Q000502:physiology; D004386:Duodenum / Q000187:drug effects* / Q000502:physiology; D006162:Guanylate Cyclase / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D015221:Potassium Channels / Q000502:physiology; D011817:Rabbits
chemical_list: D020746:Calcium Channels, L-Type; D002839:Chromans; D015221:Potassium Channels; D051546:Cyclooxygenase 2; D000262:Adenylyl Cyclases; D006162:Guanylate Cyclase; C010643:6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid