Inhibitory effect of anticholinergics on the contraction of isolated caprine urinary bladder detrusor muscle

Abstract

This study investigated whether four anticholinergics which are not clinically used for relaxing the urinary bladder detrusor muscle inhibit the contraction of isolated caprine (goat) detrusor muscle: cyclopentolate (100 nm), homatropine (5 microm), ipratropium (500 nm) and valethamate (1 microm). The effects of these anticholinergics were compared with tolterodine (3 microm), an anticholinergic clinically used for relaxing the detrusor muscle. The inhibitory effect of each of these five anticholinergics was studied on six strips of caprine detrusor muscle made to contract with 100 mum acetylcholine (ACh) by determining the percent inhibition of height of contraction and the area under the contractile curve (AUC). It was found that all five anticholinergics inhibited the ACh-induced contraction of the caprine detrusor and that this inhibition was reversed by raising the concentration of ACh. Hence, these four anticholinergics, like tolterodine, may be useful in managing clinical conditions that require relaxation of the detrusor muscle.

Avanafil inhibits the contractility of the isolated caprine detrusor muscle

“…Goat bladder was chosen for this study because of easy availability. [9] The urinary bladder samples were transported to the pharmacology laboratory in physiological salt solution (PSS). The composition of the PSS was in mM: Nacl: 111.5; KCl: 4.6; MgSO 4 : 1.16; NaH 2 PO 4 : 1.16; CaCl 2 : 2.5; NaHCO 3 : 21.9; and glucose: 11.1.…”

“…In the laboratory, strips of detrusor measuring 10 mm × 3 mm were cut from the bladder samples as done previously in our laboratory. [910] The strips were observed under a hand lens to note the orientation of the muscle fibers as described previously. [9] The urothelium was removed by gentle scraping of the strips.…”

“…[910] The strips were observed under a hand lens to note the orientation of the muscle fibers as described previously. [9] The urothelium was removed by gentle scraping of the strips. The strips were mounted in an organ bath containing adequately oxygenated PSS maintained at a temperature of 37°C.…”

“…Contractility was computed by measuring the maximum height of contraction and the area under the contractile curve (AUCC) of the tracings, a method which we have standardized in our laboratory. [78910] These parameters were calculated by scanning the tracings after each experiment and analysis using the software Image Tool (University of Texas Health Sciences Center at San Antonio, TX, USA). The percentage inhibition of the height of contraction and the AUCC following the administration of the test drug(s), that is, avanafil or avanafil with the reversal agent, in comparison with the prior administration of KCl, was calculated.…”

Inhibition of Contractility of Isolated Caprine Detrusor by the Calcium Channel Blocker Cilnidipine and Reversal by Calcium Channel Openers

“…Caprine detrusor was chosen because of easy availability and because its use has been standardized in our laboratory. 13 , 14 , 15 It was believed that the data from such a study could help facilitate the introduction of cilnidipine for the treatment of clinical conditions such as overactive bladder (OAB) requiring detrusor muscle relaxation. OAB is a chronic medical condition with a point prevalence of about 16.5% and has a major effect on the quality of life in affected men and women, influencing daily activities and social functions and interactions.…”