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Inhibition by calcium antagonists of histamine release and calcium influx of rat mast cells: Difference between induction of histamine release by concanavalin A and compound 48/80

1982; Elsevier BV; Volume: 85; Issue: 2 Linguagem: Inglês

10.1016/0014-2999(82)90460-5

1879-0712

Tamiko Suzuki, Kazuya Mori, Masaatsu K. Uchida,

Receptor Mechanisms and Signaling

The relation between calcium influx and histamine release from rat mast cells was investigated. When purified mast cells pretreated with a calcium antagonist (MnCl2 or methoxyverapamil (D-600)) were exposed to concanavalin A or compound 48/80 in Tyrode solution (pH 7.4) at 37°C, the calcium antagonists inhibited the extracellular calcium-dependent component of concanavalin A-induced histamine release. MnCl2 also inhibited the extracellular calcium-dependent component of compound 48/80-induced histamine release, whereas D-600 did not inhibit the release. D-600 inhibited the 45Ca uptake induced by concanavalin A, but did not inhibit the 45Ca uptake induced by compound 48/80. It was found that the inhibitory action of calcium antagonists depended on the uptake of extracellular calcium. These observations suggest that concanavalin A and compound 48/80 stimulate different mechanisms of calcium influx. Studies on inactivation of the mechanisms of calcium influx showed that calcium influx into cells activated by concavalin A stopped when concanavalin A was washed out, whereas the influxactivated by compound 48/80 was still operative after compound 48/80 had been washed out.