title: Evidence for the presence of P2y and P2x receptors with different functions in mouse stomach.
abstract: To clarify the function of P2 receptor subtypes in mouse stomach, the motor responses to ATP, alpha,beta-methyleneATP (alpha,beta-MeATP), P2X receptor agonist, 2-methylthioATP (2-MeSATP), P2Y receptor agonist, and the effects of the desensitisation of P2X receptors with alpha,beta-MeATP and of P2Y receptors with ADPbetaS were analysed recording the endoluminal pressure from whole-organ. ATP-induced relaxation was antagonised by suramin, non-selective P2 receptor antagonist, by desensitisation of P2Y receptors with ADPbetaS, and increased by desensitisation of P2X receptors with alpha,beta-MeATP. alpha,beta-MeATP produced biphasic responses: relaxation, reduced by P2X- or P2Y desensitisation, and contraction, almost abolished by P2X desensitisation and potentiated by P2Y desensitisation. 2-MeSATP induced relaxation, which was antagonised by P2Y desensitisation and increased by P2X desensitisation. Tetrodotoxin increased the relaxation induced by purines and deeply antagonised the contraction to alpha,beta-MeATP. Our results suggest that in mouse stomach are present muscular P2Y receptors, subserving relaxation, and neuronal presynaptic P2X receptors, mediating contraction.
authors.affiliation: Dipartimento di Biologia cellulare e dello Sviluppo, Laboratorio di Fisiologia generale, Università di Palermo, Italy. fmule@unipa.it
authors.forename: Flavia
authors.initials: F
authors.lastname: Mulè
authors.forename: Davide
authors.initials: D
authors.lastname: Naccari
authors.forename: Rosa
authors.initials: R
authors.lastname: Serio
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D009119:Muscle Contraction / Q000187:drug effects; D009126:Muscle Relaxation / Q000187:drug effects; D018048:Receptors, Purinergic P2 / Q000502:physiology*; D058469:Receptors, Purinergic P2X; D013270:Stomach / Q000187:drug effects / Q000502:physiology*; D013779:Tetrodotoxin / Q000494:pharmacology; D013873:Thionucleotides / Q000494:pharmacology
chemical_list: D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X; D013873:Thionucleotides; C030812:adenosine 5'-O-(2-thiodiphosphate); D013779:Tetrodotoxin; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate; C008501:2-methylthio-ATP