title: Antagonism of P2X receptors in guinea-pig vas deferens by diinosine pentaphosphate.
abstract: Diinosine pentaphosphate (Ip5I) antagonized contractions, mediated via P2X receptors, evoked by diadenosine pentaphosphate (Ap5A) and ATP in the guinea-pig isolated vas deferens with pA2 values of 6.4 +/- 0.17 (10 d.f.) and 6.5 +/- 0.10 (10 d.f.), respectively. Ip5I (30 microM) did not affect contractile responses evoked by noradrenaline. Ip5I (up to 100 microM) did not antagonize P2Y receptors in the guinea-pig taenia coli, nor P1 or P2 receptors in the guinea-pig left atrium.
authors.affiliation: Department of Anatomy and Developmental Biology, University College, London, UK. c.hoyle@ucl.ac.uk
authors.forename: C H
authors.initials: CH
authors.lastname: Hoyle
authors.forename: J
authors.initials: J
authors.lastname: Pintor
authors.forename: J
authors.initials: J
authors.lastname: Gualix
authors.forename: M T
authors.initials: MT
authors.lastname: Miras-Portugal
mesh_terms: D000818:Animals; D015226:Dinucleoside Phosphates / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006325:Heart Atria / Q000187:drug effects; D066298:In Vitro Techniques; D008297:Male; D009130:Muscle, Smooth / Q000187:drug effects; D009638:Norepinephrine / Q000494:pharmacology; D058915:Purinergic P1 Receptor Antagonists; D058919:Purinergic P2 Receptor Antagonists; D014649:Vas Deferens / Q000187:drug effects* / Q000378:metabolism
chemical_list: D015226:Dinucleoside Phosphates; D058915:Purinergic P1 Receptor Antagonists; D058919:Purinergic P2 Receptor Antagonists; C109479:diinosine pentaphosphate; D009638:Norepinephrine