Histochemical changes of peripheral blood leukocytes during lithium treatment

The effect of lithium on the histochemistry of blood granulocytes was studied in 16 manic-depressive patients during lithium prophylaxis. Blood smears obtained before, at 2 months and at 12 months after initiation of treatment showed that lithium caused condensation of the chromatin in granulocytes, conformation changes in eosinophilic granules and the disappearance of basic proteins found in the cytoplasm of eosinophils in the drug-free patients. The latter findings are interpreted as indicating the involvement of lithium in histamine metabolism.