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Urothelium‐dependent and urothelium‐independent detrusor contractility mediated by nitric oxide synthase and cyclooxygenase inhibition
Author(s) -
Santoso Aneira Gracia Hidayat,
Lo Wan Ning,
Liang Willmann
Publication year - 2011
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.21015
Subject(s) - urothelium , carbachol , contractility , nitric oxide synthase , nitric oxide , medicine , endocrinology , cyclooxygenase , detrusor muscle , inhibitory postsynaptic potential , arginine , electrical impedance myography , macula densa , stimulation , urinary bladder , chemistry , enzyme , biochemistry , vasodilation , amino acid , renin–angiotensin system , blood pressure
Aims The urothelium has been implicated in regulating detrusor smooth muscle contractility but the identity of the putative urothelium‐derived inhibitory factor remains unconfirmed. There was inconclusive evidence on the role of nitric oxide synthase (NOS) and cyclooxygenase (COX) in mediating detrusor contractions. This study examined varying regulation by NOS and COX in transverse and longitudinal carbachol (CCh)‐induced and unstimulated phasic contractions. Methods Rat detrusor strips with the urothelium‐intact (+UE) and urothelium‐denuded (−UE) were isolated in both transverse and longitudinal directions. Isometric tension of the detrusor strips was recorded both during stimulation with CCh and at the unstimulated state. In the unstimulated state, phasic contractile activity was measured. Tension recordings were made with and without the NOS inhibitor N ω ‐nitro‐ L ‐arginine methyl ester ( L ‐NAME) and COX inhibitor indomethacin (Indo). Results Only transverse +UE strips responded convincingly to L ‐NAME and Indo treatment, generating larger CCh‐induced contractions. In unstimulated tissues, L ‐NAME treatment increased phasic amplitude in −UE strips only. Indo treatment failed to elicit any change in the amplitude but suppressed frequency of the phasic activity in transverse +UE strips. There was no significant Indo‐mediated change in other strips. Conclusions The data suggested heterogeneity in the regulation of directional detrusor contractility via NOS‐ and COX‐associated mechanisms. Neurourol. Urodynam. 30:619–625, 2011. © 2011 Wiley‐Liss, Inc.