Extracellular magnesium decreases the secretory response of rat peritoneal mast cells to compound 48/80 in vitro.
Exposure of rat peritoneal mast cells to magnesium in the absence of extracellular calcium resulted in a time- and dose-dependent decrease in the secretory response induced by compound 48/80. The decrease was prevented by a low extracellular concentration of calcium. Furthermore, the decreased secretory responsiveness was dose-dependently restored by the addition of calcium to the cells simultaneously with compound 48/80. Preincubation with magnesium also inhibited antigen-induced histamine secretion in a dose-dependent manner. This was reversed by the simultaneous addition of calcium and the secretory stimulus. A dose-dependent decrease in antigen induced histamine secretion that was reversed by calcium was also observed. Exposure of the mast cells to magnesium for 15 min resulted in a parallel decrease in histamine secretion and in the cellular content of 45Ca2+. These observations suggest that magnesium may decrease the secretory response by displacing the cellular calcium which is utilized in stimulus-secretion coupling.
Bertelsen
H
H
Department of Pharmacology, Medical School, Odense University, Denmark.
Johansen
T
T
D000818:Animals; D000941:Antigens / Q000276:immunology; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006636:Histamine Release / Q000187:drug effects*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism*; D010529:Peritoneal Cavity / Q000166:cytology; D051381:Rats; D011919:Rats, Inbred Strains; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology*
D000941:Antigens; D003189:p-Methoxy-N-methylphenethylamine; D008274:Magnesium; D002118:Calcium