Inhibitory effects of propiverine on rat and guinea-pig urinary bladder muscle.
In muscle strips isolated from guinea-pig and rat urinary bladder, propiverine (3-10 microM) inhibited carbachol-induced contractions in the presence of verapamil and Ca(2+)-induced contractions in excess K+ medium containing atropine, suggesting it has both anticholinergic and Ca2+ channel blocking actions. The Ca2+ channel blocking action was also demonstrated by recording inward Ca2+ currents in single cells dispersed from both species. The inhibition of inward currents by propiverine was three times stronger in the rat than the guinea-pig, ID50 being 7 microM for rat and 21 microM for guinea-pig. The recovery of the current after washout was faster than that of mechanical inhibition. It is concluded that propiverine blocks not only muscarinic receptors, but also Ca2+ channels at similar concentrations.
Tokuno
H
H
Department of Physiology, School of Medicine, Nagoya University, Japan.
Chowdhury
J U
JU
Tomita
T
T
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001561:Benzilates / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects; D002217:Carbachol / Q000494:pharmacology; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D001743:Urinary Bladder / Q000187:drug effects*
D001561:Benzilates; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010276:Parasympatholytics; C015586:propiverine; D001285:Atropine; D002217:Carbachol; D011188:Potassium