Specificity of anti-leukotriene actions of nicardipine

The calcium channel blocker, nicardipine (100 ng/ml) markedly antagonized the coronary vasoconstrictor effect of the peptide leukotrienes LTC4 and LTD4 on the isolated perfused cat coronary artery. However, nicardipine even at 300 ng/ml failed to antagonize the leukotriene induced contraction of either tracheal or pulmonary parenchymal strips from guinea pigs. However, at higher concentrations (i.e., 10 micrograms/ml), nicardipine inhibited the production of peptide leukotrienes from minced cat lung incubated in the presence of A23187. Thus, nicardipine exerts some selectivity in its anti-leukotriene actions.