Inhibition of calcium entry induced by cularines and isocrasifoline in uterine smooth muscle.
The effects of nifedipine, papaverine and four benzylisoquinoline alkaloids (cularine, cularidine, celtisine and isocrasifoline) were studied in isolated rat uterus in order to clarify the mechanism of their relaxant action. All the compounds tested completely relaxed KCl-induced contractions and totally or partially inhibited oxytocin-induced rhythmic contractions. Only papaverine acted intracellularly, promoting relaxation of contractile responses induced by oxytocin or vanadate in a Ca(2+)-free medium. In spite of the structural relationship between papaverine and the other alkaloids, the mechanism of their relaxant action is not the same. The activities of cularine derivatives and of isocrasifoline were similar to that of nifedipine.
D'Ocon
P
P
Departamento de Farmacología y Farmacotecnia, Facultad de Farmacia, Universidad de Valencia, Spain.
Blasco
R
R
Candenas
L
L
Ivorra
D
D
López
S
S
Villaverde
C
C
Castedo
L
L
Cortes
D
D
D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003374:Coumarins; D005260:Female; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology*; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009543:Nifedipine / Q000494:pharmacology; D010121:Oxytocin / Q000494:pharmacology; D010208:Papaverine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D014590:Uterine Contraction / Q000187:drug effects*; D014638:Vanadates / Q000494:pharmacology
D000470:Alkaloids; D003374:Coumarins; D007546:Isoquinolines; C070415:isocrasifoline; D014638:Vanadates; D010121:Oxytocin; C070411:cularidine; C070413:celtisine; D010208:Papaverine; C064577:cularine; D009543:Nifedipine; D002118:Calcium