Aims of study:
@EN Present study designed to observe inhibitory effects of propiverine HCI and tiropramide against the smooth muscle contraction of female rat bladder. Propiverine has both direct smooth muscle relaxation and anticholinergic effect and has
relatively
fewer side effect than conventionally used drugs such as oxybutinin.
Tiropramide has been known as modulatory agents of gastriointestinal motility but also has inhibitory effects against the bladder contraction.
@ES Methods: 30 adult female Sprague Dawley rats were used. Bladder body above ureteral orifice was resected under pentobarbital anesthesia. 1×0.5cm sized smooth muscle strip was made, and incubated in Tyrode's solution aerated with 95% oxygen.
After
reaching equlibrium state, each strip was stimulated by field stimulation (FS, 1-32 Hz) and bethanechol administration (10E-7-10E-4M). From each strip, degree of muscle contraction was recorded by physiograph (Gilson IC-MP). After the control
stimulations, each strip was treated by atropine, tiropramide, oxybutinin and propiverine HCI. After 30 minutes, same stimulation were repeated and degree of muscle contraction was compared to pre incubation data.
@ES Results:
@EN Frequency and dose dependant muscle contractions were noted for both FS and bethanechol stimulation. Greater degree of contractions were noted for FS than for bethanechol stimulation.
Inhibitory effects of tiropramide, propiverine HCI and oxybutinin were greater than those of atropine at FS (1-32 Hz). At high concentration (10E-4M), all of the drugs but atropine inhibited field stimulated mooth muscle contraction more than
90%.
At
lower concentration (10E-7-10E-6M), inhibitory actions of oxybutinin and propiverine HCI were greater than that of tiropramide (p>0.05). Propiverine HCI and oxybutinin had similar inhibitory effect for all concentration. At higher concentration
(10E-4M), inhibitory effects of tiropramide were more than 98% whereas those of oxybutinin and propiverine HCI were 88%. At low concentration (10E-7-10E-6M), oxybutinin exhibited greater inhibition against the bethanechol induced contration than
did
tiropramide and propiverine HCI.
With these results, it was suggested that in low concentration, oxybutinin and propiverine HCI had greater inhibitory effect than did tiropramide against smooth muscle contraction of the bladder. In high concentration though, tiropramide had
superior
effect than did oxybutinin and propiverine HCI.
Since, no difference was noted between oxybutinin and propiverine HCI for the inhibitory action of bladder contraction, propiverine HCI seems reasonable substitute for the treatment of detrusor hyperreflexia with less side effects. Also these
results
indicate that tiropramide can be used for the management of unstable bladder.
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