Nisoldepine inhibits formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) receptor-coupled calcium transport in human neutrophils.

The formyl-methionyl-leucyl-phenylalanine (fMet-Leu-Phe) dependent Ca2+ uptake by human neutrophils consists of at least two components, one of which is sensitive to dihydropyridine derivatives. Inhibition by dihydropyridine derivatives showed the rank order of nisoldepine greater than nitrendipine greater than nimodepine greater than/Bay K 8644. The nisoldepine-sensitive calcium uptake exhibited an ID50 of 1.5 microM and maximal inhibition were observed at 5 microM. Neither calcium efflux or [3H]fMet-Leu-Phe binding was affected by nisoldepine up to 10 microM. The inhibition of nisoldepine was inversely proportional to the extracellular calcium concentration. Unlabeled nisoldepine and other dihydropyridine derivatives displaced the specific binding of [3H]PN 200-110 to human neutrophils. Our data suggest a relationship between dihydropyridine binding and the inhibition of fMet-Leu-Phe-dependent Ca2+ uptake.