Differences in Transverse and Longitudinal Rat Detrusor Contractility Under K+ Channel Blockade

β-Adrenoceptor-mediated differences in transverse and longitudinal strips from the rat detrusor

“…The difference, or lack thereof, in transverse and longitudinal contractions may depend on the stimulus, as well as age and species from where the bladder originates [8,9]. The evidence thus far supports that the concentration-response relationship of carbachol (CCh)-induced contractions is indistinguishable between transverse and longitudinal directions in the rat detrusor [8,9]. Relaxations, however, have yet to be compared between the two directions.…”

Differential Effects of K<sup>+</sup> Channel Blockers on Phasic Contractility of Transverse and Longitudinal Rat Detrusor Strips

“…Both urothelium-intact and -denuded detrusor tissues from the bladder of different species have been used, often yielding conflicting results [5,6,8,12,13]. Thus, generalizations, if any, about K + -channel-mediated phasic contractions in the detrusor are yet to be made.…”

“…Differences in contractile directions, i.e. transverse vs. longitudinal, in the detrusor have been reported under different experimental conditions [11][12][13][14][15]. Choice of species and method of tissue preparation (i.e.…”

“…Findings from the normal rat bladder therefore provide good references to identify diseased-induced changes in disease models. The vast majority of literature on bladder contractility of the rat (or other animals) reported on longitudinal contractions only, irrespective of contractile differences between transverse and longitudinal directions [11][12][13][14][15]. These differences point to the importance in considering contractions in more than one direction.…”

“…After another 30 minutes of continuous washout, a K + channel blocker was added. The effective concentration of each K + channel blocker in rat detrusor strips was pre-determined in previous studies [12,13]. Blockers used were as follows (concentrations in parentheses): tetraethylammonium chloride (TEA, 10 mM), 4-aminopyridine (4-AP, 3 mM), glibenclamide (Glib, 0.1 µM), iberiotoxin (IbTx, 0.1 µM), charybdotoxin (ChTx, 0.1 µM) and apamin (0.1 µM).…”