title: Evidence that ATP is a neurotransmitter in the frog heart.
abstract: In the presence of atropine, electrical field stimulation of frog atria produced a positive inotropic response. This response had two components. The initial phase was blocked by selective desensitization of P2-purinoceptors with alpha, beta-methylene ATP. The second phase, which was not always clearly separated from the initial phase, was blocked by the beta-adrenoceptor antagonist propranolol. The present results suggest that ATP may be a cotransmitter released with adrenaline from nerve terminals of the vagosympathetic trunk supplying the frog atria.
authors.forename: C H
authors.initials: CH
authors.lastname: Hoyle
authors.forename: G
authors.initials: G
authors.lastname: Burnstock
mesh_terms: D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000502:physiology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004558:Electric Stimulation; D004837:Epinephrine / Q000494:pharmacology; D006321:Heart / Q000294:innervation*; D066298:In Vitro Techniques; D008297:Male; D018377:Neurotransmitter Agents; D011433:Propranolol / Q000494:pharmacology; D011896:Rana temporaria
chemical_list: D018377:Neurotransmitter Agents; C523965:alpha,beta-methyleneadenosine 5'-diphosphate; D000244:Adenosine Diphosphate; D001285:Atropine; D000255:Adenosine Triphosphate; D011433:Propranolol; D004837:Epinephrine