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Comparison of the anticonstrictor action of dihydropyridines (nimodipine and nicardipine) and Mg2+ in isolated human cerebral arteries

1992; Elsevier BV; Volume: 229; Issue: 1 Linguagem: Inglês

10.1016/0014-2999(92)90289-g

1879-0712

Enrique Alborch, Juan B. Salom, Alfredo J. Perales, Germán Torregrosa, Francisco J. Miranda, JoséA. Alabadí, Teresa Jover,

Lanthanide and Transition Metal Complexes

The isometric tension recorded from ring segments of branches of human middle cerebral artery was the parameter used to study the inhibition of spasmogen-induced contractions as model for cerebral vasospasm. Concentration-response curves to 5-hydroxytryptamine (10−9−3 × 10−5 M) and prostaglandin F2α (10−7−3 × 10−5 M) were inhibited in Ca2+-free medium and in Ca2+-free medium to which EGTA (1 mM) had been added, respectively. Nimodipine (10−7, 10−5 M), nicardipine (10−7, 10−5 M) and Mg2+ (magnesium sulfate 10−4, 10−2 M) inhibited the 5-HT-elicited contractions, and this inhibition was similar for the highest concentrations tested. In contrast, nimodipine and nicardipine were more effective than Mg2+ to inhibit the prostaglandin F2α-elicited contractions. Nimodipine (10−9−10−5 M), nicardipine (10−9−10−5 M) and Mg2+ (10−5 − 3 × 10−2 M) relaxed the arteries precontracted with PGF2α (10−5 M), but nicardipine was the most potent relaxant drug. Because 5-hydroxytryptamine and prostaglandin F2α may be involved in the pathogenesis of cerebral vasospasm, nimodipine, nicardipine, and Mg2+ could be used in the pharmacological treatment of this disorder. However, dihydropyridines (particularly nicardipine) are more potent anticonstrictors than Mg2+.