To clarify the function of P2 receptor subtypes in mouse stomach, the motor responses to ATP, a,h-methyleneATP (a,h-MeATP), P2Xreceptor agonist, 2-methylthioATP (2-MeSATP), P2Y receptor agonist, and the effects of the desensitisation of P2X receptors with a,h-MeATP and of P2Y receptors with ADPhS were analysed recording the endoluminal pressure from whole-organ. ATP-induced relaxationwas antagonised by suramin, non-selective P2 receptor antagonist, by desensitisation of P2Y receptors with ADPhS, and increased bydesensitisation of P2X receptors with a,h-MeATP. a,h-MeATP produced biphasic responses: relaxation, reduced by P2X- or P2Ydesensitisation, and contraction, almost abolished by P2X desensitisation and potentiated by P2Y desensitisation. 2-MeSATP inducedrelaxation, which was antagonised by P2Y desensitisation and increased by P2X desensitisation. Tetrodotoxin increased the relaxationinduced by purines and deeply antagonised the contraction to a,h-MeATP. Our results suggest that in mouse stomach are present muscularP2Y receptors, subserving relaxation, and neuronal presynaptic P2X receptors, mediating contraction.
|Numero di pagine||6|
|Rivista||European Journal of Pharmacology|
|Stato di pubblicazione||Published - 2005|
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