title: Bradykinin facilitates the purinergic motor component of the rat bladder neurotransmission.
abstract: The motor activity of the rat bladder elicited by transmural electrical stimulation was abolished in the presence of 200 nM tetrodotoxin but not of 1 microM atropine plus 3.4 microM guanethidine. Tissue preincubation with 20 microM, alpha, beta-methylene ATP reduced but did not obliterate the electrically-induced motor effect. Bradykinin (BK) caused a short-lasting motor response while it potentiated, in a concentration-dependent fashion, the 0.15-5 Hz-induced muscle twitching. The facilitatory action of the peptide lasted for at least 5 min and was blocked by the BK-B2 receptor antagonist D-Arg0 [Hyp3, Thi5,8, D-Phe7]-BK. The motor response caused by the exogenous application of adenosine 5'-triphosphate (ATP) was almost immediate and lasted less than 30 s; it was also potentiated by BK-B2 receptor activation, an effect that was reduced in a concentration-dependent manner by pretreatment with the BK-receptor antagonist.
authors.affiliation: Department of Physiological Sciences, Faculty of Biological Sciences, University of Concepción, Chile.
authors.forename: C G
authors.initials: CG
authors.lastname: Acevedo
authors.forename: J
authors.initials: J
authors.lastname: Lewin
authors.forename: E
authors.initials: E
authors.lastname: Contreras
authors.forename: J P
authors.initials: JP
authors.lastname: Huidobro-Toro
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D004558:Electric Stimulation; D066298:In Vitro Techniques; D009046:Motor Neurons / Q000187:drug effects / Q000502:physiology*; D011687:Purines / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D001743:Urinary Bladder / Q000294:innervation* / Q000502:physiology
chemical_list: D011687:Purines; D000255:Adenosine Triphosphate; D001920:Bradykinin