Fernandes Ribeiro, Ana SofíaFernandes, Vítor S.Martínez Sainz, María Del PilarLópez-Oliva Muñoz, María ElviraBarahona Gomáriz, María VictoriaRecio Visedo, María PazMartínez Gómez, Ana CristinaBlaha, IgorOrensanz Muñoz, Luis MiguelBustamante, SalvadorGarcía Sacristán, AlbinoPrieto Ocejo, DoloresHernández Rodríguez, Medardo Vicente2024-02-012024-02-012016Ribeiro AS, Fernandes VS, Martínez MP, et al. Pre- and post-junctional bradykinin B2 receptors regulate smooth muscle tension to the pig intravesical ureter. Neurourol Urodyn. 2016;35(1):115-121. doi:10.1002/nau.226850733-246710.1002/nau.22685https://hdl.handle.net/20.500.14352/97696Aims Neuronal and non-neuronal bradykinin (BK) receptors regulate the contractility of the bladder urine outflow region. The current study investigates the role of BK receptors in the regulation of the smooth muscle contractility of the pig intravesical ureter. Methods Western blot and immunohistochemistry were used to show the expression of BK B1 and B2 receptors and myographs for isometric force recordings. Results B2 receptor expression was consistently detected in the intravesical ureter urothelium and smooth muscle layer, B1 expression was not detected where a strong B2 immunoreactivity was observed within nerve fibers among smooth muscle bundles. On ureteral strips basal tone, BK induced concentration-dependent contractions, were potently reduced by extracellular Ca2+ removal and by B2 receptor and voltage-gated Ca2+ (VOC) channel blockade. BK contraction did not change as a consequence of urothelium mechanical removal or cyclooxygenase and Rho-associated protein kinase inhibition. On 9,11-dideoxy-9a,11a-methanoepoxy prostaglandin F2α (U46619)-precontracted samples, under non-adrenergic non-cholinergic (NANC) and nitric oxide (NO)-independent NANC conditions, electrical field stimulation-elicited frequency-dependent relaxations which were reduced by B2 receptor blockade. Kallidin, a B1 receptor agonist, failed to increase preparation basal tension or to induce relaxation on U46619-induced tone. Conclusions The present results suggest that BK produces contraction of pig intravesical ureter via smooth muscle B2 receptors coupled to extracellular Ca2+ entry mainly via VOC (L-type) channels. Facilitatory neuronal B2 receptors modulating NO-dependent or independent NANC inhibitory neurotransmission are also demonstrated. Neurourol. Urodynam. 35:115–121, 2016. © 2014 Wiley Periodicals, Inc.engjournal article1520-6777https://doi.org/10.1002/nau.22685open access61612.019Bradykinin receptorsCa2+SignalingInhibitory neurotransmission modulationPig intravesical ureterSmooth muscle tensionCiencias BiomédicasFisiología veterinaria24 Ciencias de la Vida