Low concentrations of niflumic acid enhance basal spontaneous and carbachol-induced contractions of the detrusor

• Published in: International urology and nephrology Vol. 46; no. 2; pp. 349 - 357
• Main Authors: Lam, Wai Ping, Tang, Hong Chai, Zhang, Xin, Leung, Ping Chung, Yew, David Tai Wai, Liang, Willmann
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.02.2014; Springer Nature B.V
• Subjects: Animals; Carbachol - pharmacology; Cholinergic Agonists - pharmacology; Cyclooxygenase Inhibitors - pharmacology; Dose-Response Relationship, Drug; Isometric Contraction - drug effects; Male; Medicine; Medicine & Public Health; Mucous Membrane - physiology; Muscle, Smooth - drug effects; Muscle, Smooth - physiology; Nephrology; Niflumic Acid - pharmacology; Rats; Rats, Sprague-Dawley; Urinary Bladder - drug effects; Urinary Bladder - physiology; Urology; Urology - Original Paper; Niflumic acid; Detrusor; Mucosa; Contraction
• ISSN: 0301-1623; 1573-2584
• DOI: 10.1007/s11255-013-0550-8

Purpose The urinary bladder expresses Ca 2+ -activated Cl − channels (CACC), but its physiological role in governing contractility remains to be defined. The CACC modulator niflumic acid (NFA) is widely used despite the variable results arisen from different drug concentrations used. This study was designed to examine the effects of NFA at low concentrations on detrusor strip contractility. Methods Rat detrusor strips with mucosa-intact (+MU) and mucosa-denuded (−MU) were prepared in transverse (Tr) and longitudinal (Lg) with respect to the bladder orientation. Isometric force measurements were made at baseline (for spontaneous phasic contractile activity) and during drug stimulation (by carbachol, CCh) with and without NFA. Results NFA (1 and 10 μmol/L) pretreatment enhanced CCh-induced contractions more in +MU than −MU strips with no selectivity on contractile direction. For spontaneous phasic contractions, NFA-treated strips in the Tr direction showed increased phasic amplitude, while phasic frequency was unchanged. Conclusions The findings suggest low concentrations of NFA having a potentiating effect on detrusor contractions that was sensitive to the MU and contractile direction.