Further thoughts on mast cells, calcium channels and histamine release

Calcium movements across membranes of mast cells represent a major target for effective anti-allergic drugs, as these are essential events linking stimulation to secretion. Using isolated peritoneal mast cells from two types of genetically different rats and a blocker of the entry of calcium ions into cells, histamine release induced by antigen, calcium ionophore and potassium (in a lowered calcium medium) has been followed. Lower concentrations of the calcium entry blocker were required to inhibit potassium-induced release than those needed for release induced by allergic and other non-allergic stimuli, suggesting that different specialised calcium channels are involved in histamine release from rat mast cells.