Control of histamine release: effects of various conditions on rate of release and rate of cell desensitization.

Histamine release from rat mast cells by dextran and by antigen under various conditions was studied in terms of the rate of release and the duration of release, which together determined the total amount released. Reducing the concentration of the releasing agent decreased the rate of release without greatly affecting its duration. Reducing the temperature also decreased the rate, but prolonged the duration. Under all of the various conditions, release stopped as the cells became desensitized to the releasing agent. It appeared, therefore, that the rate of desensitization controlled the duration of release.