Modulation of the rate of histamine release from basophils by cyclic AMP

Rates of histamine release from human basophil leukocytes have been studied in response to three different stimuli: antigen, ionophore A23187 and strontium ions. Dibutyryl cycle AMP and other agents which are assumed to cause a rise in intracellular levels of cyclic AMP accelerate the release of histamine induced by all of the stimuli. In addition, dibutyryl cyclic AMP caused an inhibition of the maximum release obtainable with antigen stimulation but no inhibition of the maximum release obtainable with ionophore A 23187 or with strontium ions alone.