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Neuronal‐derived nitric oxide modulates the activity of mouse detrusor smooth muscle
Author(s) -
Meng E.,
Young J.S.,
Cha T.L.,
Sun G.H.,
Yu D.S.,
Brading A.F.
Publication year - 2012
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.21247
Subject(s) - nitric oxide , contractility , contraction (grammar) , detrusor muscle , electrophysiology , medicine , interstitial cell of cajal , snap , electrical impedance myography , muscle contraction , premovement neuronal activity , neuronal nitric oxide synthase , endocrinology , urinary bladder , nitric oxide synthase , smooth muscle , neuroscience , biology , vasodilation , computer graphics (images) , computer science
Aims We investigated the roles of neuronal‐derived nitric oxide (NO) in the modulation of spontaneous activity of mouse detrusor smooth muscle. Methods Detrusor smooth muscle strips were isolated from nNOS gene knock‐out (nNOS −/− ) mice and their wild type siblings (nNOS +/+ ). The properties of smooth muscle cells were assessed using intracellular electrophysiology and Ca 2+ imaging by laser‐scanning confocal microscopy. The effects of an nNOS inhibitor, 7‐nitro indazole (7‐NI) on electrically evoked contractility were assessed using nNOS +/+ mouse detrusor strips. Results In spontaneously active cells, the frequency of spontaneous action potentials (sAPs) and whole cell Ca 2+ flashes in nNOS −/− preparations was lower than that in the nNOS +/+ preparations. The frequency of sAPs was enhanced by a nitric oxide donor, diethylamine NONOate sodium salt (NONOate; 100 µM), both when used alone and when the cGMP pathway was blocked by 1H‐[1,2,4] oxadiazolo [4,3‐a] quinoxalin‐1‐one (ODQ, 10 µM). 7‐NI (100 µM) significantly suppressed the electrically evoked contraction of mouse detrusor strips. Conclusions We suggest that neuronal‐derived NO facilitates the generation of spontaneous activity via a cGMP‐independent pathway, and consequently enhances the evoked contraction of detrusor. Dysregulation of nNOS containing nerves may underlie bladder pathologies. Neurourol. Urodynam. 31:572–578, 2012. © 2012 Wiley Periodicals, Inc.