Temperature Dependence of Histamine Release from Rat Mast Cells by Dextran

Summary

Maximal release of histamine from rat mast cells by dextran occurred at 25°. If the cell temperautre was changed from 25° to 37°, beginning promptly there-after dextran released considerably less histamine. This effect was fully reversible, however, by restoring the temperature to 25° before dextran was added. Studies employing a wide range of dextran concentrations showed that changing the temperature from 25° to 37° systematically increased, by about two orders of magnitude, the dextran concentration required to produce the same degree of release as obtained at 25°. The amount of histamine released at 37° relative to that released at 25° varied markedly as dextran concentration was changed.

Note added in proof. We have now carried out experiments with cells obtained from rats immunized with egg albumin and pertussis vaccine. When such cells were challenged with the antigen (egg albumin) in concentrations ranging from 10^-10 to 10^-1 mg/ml at 25° and at 37°, results similar to those shown in Fig. 4 for dextran were obtained. With the higher antigen concentrations, however, release at 37° often exceeded that at 25°. We believe that the quantity of histamine released by dextran or by antigen is dependent on the rate of release and the rate of cell desensitization, both of which are influenced by the environmental conditions (Baxter, J. H. and Adamik, R. Fed. Proc. 33, 761, 1974).