Effects of oxodipine and elgodipine on (+)-[3H]-isradipine binding to cardiac and vascular membranes: cardiovascular selectivity.
We studied the effects of six dihydropyridines on the specific binding of (+)-[3H]-isradipine to vascular (portal vein) and cardiac isolated membranes to achieve the relative cardiovascular selectivity of these compounds. Elgodipine, (+)-oxodipine and nifedipine had a significantly higher affinity for the vascular L-type calcium channel than for the cardiac calcium channel while nicardipine showed opposite properties. The other dihydropyridines (nitrendipine and (+)-isradipine) had similar affinities for the cardiac and vascular calcium channels. As the membrane potential of isolated membranes is about 0 mV, these results suggest that the differences in binding of these dihydropyridines to L-type calcium channels in vascular and cardiac cells may be attributed to differences in the molecular structure of these calcium channels.
Rakotoarisoa
L
L
Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, URA CNRS 1489, Université de Bordeaux II, France.
Leprêtre
N
N
Mironneau
J
J
Galiano
A
A
Mironneau
C
C
D000818:Animals; D001665:Binding Sites; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D004095:Dihydropyridines / Q000494:pharmacology*; D006736:Horses; D066298:In Vitro Techniques; D017275:Isradipine / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D011169:Portal Vein / Q000378:metabolism*; D051381:Rats
D002121:Calcium Channel Blockers; D004095:Dihydropyridines; C063839:elgodipine; C053783:oxodipine; D017275:Isradipine