Histamine release by pharmacological agents in the absence of external free Ca2+.
The involvement of extracellular free Ca2+ in histamine release was investigated in rat peritoneal mast cells. Incubation of non-antigenized cells in a media with high extracellular potassium did not increase histamine release. Secretion induced by A23187 and compound 48/80 in the presence of Ca2+ requires metabolic energy. In the absence of external free Ca2+ (2.5 microM) histamine release induced by A23187 is reduced but not abolished. Secretion induced by compound 48/80 is independent of extracellular Ca2+. These results lead us to suggest that mast cell plasma membranes probably lack voltage-gated Ca2+ channels and that external Ca2+ may not be an absolute requisite for histamine secretion.
D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects*; D007700:Kinetics; D008297:Male; D008407:Mast Cells / Q000276:immunology*; D011188:Potassium / Q000494:pharmacology; D011190:Potassium Cyanide / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D000001:Calcimycin; D005947:Glucose; D011190:Potassium Cyanide; D011188:Potassium; D002118:Calcium