E Meng, J S Young, T L Cha, G H Sun, D S Yu, A F Brading
Department of Surgery, National Defense Medical Center, Taipei, Taiwan, Republic of China. en.meng@gmail.com
Neurourology and urodynamics 2012 AprWe investigated the roles of neuronal-derived nitric oxide (NO) in the modulation of spontaneous activity of mouse detrusor smooth muscle. 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. 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. 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. Copyright © 2012 Wiley Periodicals, Inc.
E Meng, J S Young, T L Cha, G H Sun, D S Yu, A F Brading. Neuronal-derived nitric oxide modulates the activity of mouse detrusor smooth muscle. Neurourology and urodynamics. 2012 Apr;31(4):572-8
PMID: 22275213
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