Tramadol inhibits the contractility of isolated caprine detrusor muscle

Abstract

The atypical opioid analgesic tramadol has been shown to provide beneficial clinical and urodynamic effects in patients with detrusor overactivity. The effect of tramadol on isolated detrusor muscle has not been studied. This study investigated the ability of tramadol to inhibit acetylcholine (ACh)-induced contractility of the isolated caprine (goat) detrusor muscle. The effect of three concentrations (30, 100 and 300 μm) of tramadol on 10 caprine detrusor strips contracted by the addition of 100, 200 or 400 μm ACh was studied. The sensitivity of tramadol-induced inhibition of ACh responses to treatment with the β-adrenoceptor antagonist propranolol (1 μm) and the opioid receptor antagonist naloxone (100 μm) was also studied. Tramadol caused a concentration-dependent inhibition of ACh-induced detrusor contraction that was reversed by raising the concentration of ACh. Propranolol, but not naloxone, reversed the tramadol-induced inhibition of contractions to ACh in the detrusor. These results suggest that tramadol inhibits ACh-induced contractility of the isolated detrusor. They also suggest that tramadol does so by an indirect anticholinergic mechanism involving the stimulation of β-adrenoceptors. Tramadol may be useful in managing clinical conditions requiring relaxation of the detrusor muscle. Although the concentrations of tramadol needed to relax the detrusor were relatively high, these could be clinically attained via intravesical administration.

Tramadol inhibits the contractility of isolated human myometrium

“…1). We found similar results as these in a study on the effect of tramadol on acetylcholine (Ach)-induced contractility of isolated caprine detrusor muscle where the inhibition of detrusor contractility by tramadol was reversed by propranolol, but not by methylene blue or naloxone (Kumar et al, 2012). However, there was a difference in potency of tramadol in inhibiting contractility between the two studies: in the study on the myometrium, the per cent inhibition by tramadol was significant at all three concentrations (30, 100 and 300 lM) of tramadol used, whereas in the study on the detrusor, the per cent inhibition was significant only at 100 and 300 lM concentrations of tramadol and not at 30 lM.…”

“…In this light, antimuscarinic effects may explain dry mouth, which is a common adverse effect reported in patients treated with tramadol (Scott & Perry, 2000). Tramadol has also been shown to inhibit the contractility of isolated smooth muscles like rabbit aorta (Kaya et al, 2003), guinea-pig small intestine (Herbert et al, 2007) and caprine (goat) detrusor muscle (Kumar et al, 2012). To our knowledge, the effect of tramadol on the contractility of isolated myometrium has not been studied.…”

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

“…In the laboratory, strips of detrusor measuring 10 × 3 mm were cut from the bladder samples as done previously in our laboratory. 13 , 14 , 15 , 17 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.…”

“…An amount of 80 mM KCl is the standard concentration of KCl used in our laboratory for stimulating the contraction of the isolated detrusor. 13 After washing the bath, cilnidipine at a concentration of 20 µM was added to the organ bath and allowed to incubate for a period of 5 minutes. Then 80 mM KCl was added again and the contractile response was obtained.…”

“…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.…”