title: Effects of alpha beta methylene ATP on membrane potential, neuromuscular transmission and smooth muscle contraction in the rat tail artery.
abstract: alpha beta methylene ATP (meATP, 400 nM-1 microM) caused depolarization and constriction of the smooth muscle of the rat tail artery, and block of the excitatory junction potential (e.j.p.). A similar depolarization caused by 25 mM K did not block the e.j.p. Contractions caused by nerve-released noradrenaline acting on alpha-adrenoceptors were potentiated by meATP but this was probably due to the depolarization as 25 mM K had a similar effect. MeATP blocked e.j.p.s recorded in the presence of 3 microM tetrodotoxin, suggesting that meATP was not blocking e.j.p.s by a local anaesthetic action.
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000502:physiology; D009469:Neuromuscular Junction / Q000187:drug effects / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission / Q000187:drug effects
chemical_list: D000255:Adenosine Triphosphate; C002630:alpha,beta-methyleneadenosine 5'-triphosphate