The role of cell-fixed calcium in histamine release by compound 48/80.
1. Histamine release by compound 48/80 was substantially reduced in a time-dependent manner (maximum at 30 min) by pre-incubating mast cells in calcium-free medium at 37 degrees C but not at 2 degrees C. This effect was optimal at pH 7.0 to 7.5. 2. The re-introduction of calcium (0.1 to 3 mmol/l) restored histamine release to the control value; this effect was independent of temperature. 3. Strontium (1 to 30 mmol/l) partially reversed the effect of calcium deprivation but the same concentrations of barium and magnesium depressed histamine release even further. Magnesium (3 to 15 mmol/l) antagonized the effect of calcium replacement. 4. Results suggest that the level of cell-fixed calcium involved in compound 48/80-induced histamine release may be controlled by the combination of rapid passive influx and slow active efflux.
D000818:Animals; D001464:Barium / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D006636:Histamine Release / Q000187:drug effects*; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008407:Mast Cells / Q000378:metabolism; D051381:Rats; D013324:Strontium / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors; D009764:o-Phthalaldehyde / Q000494:pharmacology; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology*
D001464:Barium; D003189:p-Methoxy-N-methylphenethylamine; D009764:o-Phthalaldehyde; D008274:Magnesium; D002118:Calcium; D013324:Strontium