Ketotifen, a selective histamine liberator]

Ketotifen-induced histamine release from isolated rat mast cells is inhibited under conditions of ATP content depletion in the mast cells. The histamine release is a temperature-dependent process and is blocked at a low temperature. It is concluded that ketotifen is a selective histamine liberator. Time course of ketotifen-induced histamine release corresponds with the process of partial cellular uptake of histamine released.