Propantheline and in vitro reactivity of urinary bladder smooth muscle in guinea pigs

The aim of this study was to verify the in vitro action of propantheline on urinary bladder smooth muscle in guinea pigs and to compare its effect with previously tested oxybutynin.

The reactivity of the urinary bladder smooth muscle was estimated in vitro using organ chambers. The smooth muscle strips were prepared from guinea pig urinary bladders and aerated under the tension in Krebs-Henseleit's solution in the organ bath. The cumulative concentration-response curves to acetylcholine (10(-8)-10(-3) mol.l(-1)) were constructed before and after 15 minute incubation with propantheline in concentration of 10(-6), 10(-5), 10(-4), and 10(-3) mol.l(-1).

Propantheline caused a decrease of urinary bladder smooth muscle reactivity to acetylcholine. This decrease was statistically significant only at concentration of 10(-5), 10(-4) and 10(-3) mol.l(-1) of propantheline.

Propantheline significantly influenced the reactivity of urinary bladder smooth muscle to acetylcholine in guinea pigs. Comparing the influence of oxybutynin we can conclude that oxybutynin caused a significantly higher decrease of the reactivity to acetylcholine than propantheline. (Fig. 3, Ref. 30.)