Inhibitory effects of propiverine hydrochloride on the agonist-induced or spontaneous contractions of various isolated muscle preparations.

Inhibitory effects of propiverine hydrochloride (P-4, CAS 60569-19-9), a new drug which reduces the frequency of micturition, were studied on the agonist-induced or spontaneous contractions of various isolated muscle preparations. P-4 (10(-6)-10(-4) mol/l) inhibited both the KCl-induced contractions of isolated guinea-pig urinary bladder and ileum, and its IC50 values (mol/l) were 1.8 +/- 0.3 x 10(-5) (urinary bladder) and 1.3 +/- 0.4 x 10(-5) (ileum), respectively. The spontaneous contractions of isolated guinea-pig atrium, rat uterus and rabbit duodenum were unaffected by P-4 at 10(-6) mol/l, but they were inhibited by the drug at 10(-5)-10(-4) mol/l. Its IC50 values (mol/l) were 10(-4) greater than (guinea-pig atrium), 1.3 +/- 0.3 x 10(-4) (rat uterus), and 1.0 +/- 0.5 x 10(-4) (rabbit duodenum), respectively. P-4 (10(-5)-10(-4) mol/l) inhibited the KCl-induced contraction of isolated rabbit aorta and the histamine-induced contraction of isolated guinea-pig tracheal chain. P-4 (10(-4) mol/l) also inhibited the noradrenaline-(norepinephrine) induced contractions of isolated guinea-pig urethra and vas deferens. In these isolated muscle preparations, the values of IC50 (greater than 10(-4) mol/l) could not be calculated. These results indicate that the inhibitory activities of P-4 on urinary bladder and ileum are 10 to 100 times more potent than those on other organs.