Effects of mebudipine and dibudipine, two new calcium channel blockers, on guinea-pig isolated common bile duct.
The inhibitory effects of calcium channel blockers; nifedipine and two new compounds, mebudipine and dibudipine, on contractions of isolated guinea-pig common bile duct were investigated. All the compounds tested induced a concentration-dependent reduction of the amplitude of contractile response to electrical stimulation and all the compounds displaced concentration-response curve of calcium chloride to the right in a concentration-dependent manner. The pIC50 values for these compounds acting on electrically stimulated common bile duct were calculated as: dibudipine: 8.50 +/- 0.17; mebudipine: 8.27 +/- 0.20; nifedipine: 7.96 +/- 0.07. The compounds also antagonized the contractile response of K+-depolarized guinea-pig common bile duct to cumulative concentration of calcium. However the inhibitory effect of these compounds were not significantly different.
Beigly
S
S
Razi Institute for Drug Researches, Iran University of Medical Sciences, Shaheed Hemmat express way, Tehran, Iran.
Ghiaee
S
S
Ebrahimi
S A
SA
Mahmoudian
M
M
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003135:Common Bile Duct / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology*; D010276:Parasympatholytics / Q000494:pharmacology
D002121:Calcium Channel Blockers; D010276:Parasympatholytics; C110813:dibudipine; C110812:mebudipine; D009543:Nifedipine