title: Nitric oxide is involved in the non-adrenergic, non-cholinergic inhibitory neurotransmission of the pig intravesical ureter.
abstract: NADPH-diaphorase histochemical staining and electrical field stimulation (EFS) were performed in vitro to investigate whether nitric oxide (NO) is involved in non-adrenergic non-cholinergic (NANC) inhibitory neurotransmission of pig intravesical ureter. NADPH-diaphorase activity was expressed in nerve trunks and thin nerve fibres around arteries and muscular bundles in the intravesical ureter. Relaxations to EFS were tetrodotoxin (10(-6) M)-sensitive which indicates their neurogenic origin. Addition of the NO-synthase inhibitor, L-NG-nitroarginine (L-NOARG, 3 x 10(-5) M), abolished the electrically induced relaxations, which were significantly reversed by L-arginine (3 x 10(-3) M). Addition of acidified sodium nitrite (NaNO2, 10(-5)-10(-3) M) evoked concentration-dependent relaxations of ureteral strips which were unaffected by L-NOARG. It is concluded that NO synthase is present in nerve fibres and NO seems to mediate the inhibitory neurotransmission of the porcine intravesical ureter.
authors.affiliation: Departamento de Fisiología, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Hernández
authors.forename: D
authors.initials: D
authors.lastname: Prieto
authors.forename: L M
authors.initials: LM
authors.lastname: Orensanz
authors.forename: M V
authors.initials: MV
authors.lastname: Barahona
authors.forename: A
authors.initials: A
authors.lastname: García-Sacristán
authors.forename: U
authors.initials: U
authors.lastname: Simonsen
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001341:Autonomic Nervous System / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D006651:Histocytochemistry; D066298:In Vitro Techniques; D008297:Male; D009126:Muscle Relaxation / Q000502:physiology; D009130:Muscle, Smooth / Q000294:innervation / Q000502:physiology*; D009252:NADPH Dehydrogenase / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D019335:Nitroarginine; D013552:Swine; D009435:Synaptic Transmission / Q000502:physiology*; D016707:Tissue Fixation; D014513:Ureter / Q000294:innervation / Q000502:physiology*
chemical_list: D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine; D009252:NADPH Dehydrogenase