title: Isradipine: a potent calcium blocker with beneficial effects on platelet function and vascular prostacyclin production.
abstract: Calcium blockers inhibit platelet aggregation induced in vitro by various stimuli, such as ADP and collagen. In this study the in vitro effects of isradipine, a new dihydropyridine-derivative, and of nifedipine on platelet aggregation and malondialdehyde-production were tested. The lowest concentrations affecting ADP-induced platelet aggregation were 1.0 micrograms/ml isradipine and 12.5 micrograms/ml nifedipine. Both drugs exhibited an inhibitory action on malondialdehyde-production in concentrations 2 to 3 times lower than those affecting platelet aggregation. In vitro, PGI2-formation by rat aortic rings incubated with calcium blockers was increased in a dose-dependent manner. The lowest concentration of isradipine which increased PGI2-generation amounted 0.5 micrograms/ml. The corresponding value for nifedipine was 10 micrograms/ml. The findings demonstrate isradipine to be more potent than nifedipine in affecting in vitro platelet aggregation and enhancing PGI2-formation.
authors.affiliation: Atherosclerosis Research Group (ASF), Vienna, Austria.
authors.forename: K
authors.initials: K
authors.lastname: Weiss
authors.forename: P
authors.initials: P
authors.lastname: Fitscha
authors.forename: J
authors.initials: J
authors.lastname: O'Grady
authors.forename: H
authors.initials: H
authors.lastname: Sinzinger
mesh_terms: D000244:Adenosine Diphosphate / Q000502:physiology; D000328:Adult; D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003094:Collagen / Q000502:physiology; D011464:Epoprostenol / Q000096:biosynthesis*; D006801:Humans; D017275:Isradipine; D008297:Male; D009543:Nifedipine / Q000494:pharmacology; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D002121:Calcium Channel Blockers; D010975:Platelet Aggregation Inhibitors; D011725:Pyridines; D000244:Adenosine Diphosphate; D003094:Collagen; D011464:Epoprostenol; D009543:Nifedipine; D017275:Isradipine