Spontaneous histamine secretion from leukocytes in the presence of strontium

Basophil leukocytes from human blood secrete histamine in the absence of a membrane stimulus when incubated in a medium containing Sr++, 1 to 10 mM. Spontaneous histamine secretion in the presence of Sr++ is inhibited by La+++, 1 to 1000 nM and 2 deoxy-D-glucose, 30 to 300 microM. Spontaneous secretion in the presence of Sr++ increases with increasing pH in the range 6.5 to 8.5. Agents which cause a rise of intracellular cyclic AMP level increase the spontaneous secretion in 194th presence of Sr++. The results suggest that spontaneous histamine release is a secretory response of the cells, and evidence is provided for a dual role of cyclic AMP in the control of histamine secretion.