Histamine synthesis by bone marrow-derived macrophages.

Histamine may be involved in the regulation of hematopoiesis. However, it remained obscure what kind of cells are responsible for its synthesis in bone marrow (BM). In this study, a pure population of macrophages were raised from BM of W/Wv mice, which are genetically deficient in mast cells. The addition of Escherichia coli lipopolysaccharide (LPS) or murine recombinant granulocyte/macrophage colony-stimulating factor (mrGM-CSF) alone had essentially no effect on histamine synthesis. However, the latter rendered the cells responsive to LPS, leading to a marked increase in HDC-dependent histamine synthesis.