Histamine Synthesis by Cells of the Macrophage Lineage in Bone Marrow of Mice

Abstract

An injection of Escherichia coli lipopolysaccharide (LPS) increased the activity of histidine decarboxylase (HDC) in bone marrow (BM) cells of C3H/HeN mice much more than in C3H/HeJ mice, which are resistant to various effects of LPS. In WBB6/F1 (W/W^v) mice, which are genetically deficient in mast cells, HDC activity increased more than in C3H/HeN mice. Cultured BM cells of W/W^v mice spontaneously synthesized histamine in a HDC-dependent way. LPS caused a slight increase in HDC-associated histamine synthesis by these cells. Treatment of the BM cells with murine recombinant granulocyte-macrophage colony stimulating factor (mrGM-CSF) increased the histamine synthesis. In addition, treatment with mrGM-CSF made the cells respond to LPS by a dose-dependent increase in HDC activity and histamine synthesis. Most dish-adherent BM cells that had been treated with both mrGM-CSF and LPS for 48h were stained for nonspecific esterase and not for chloroacetate esterase, and had twice as much HDC activity as the nonadherent cells had. Immunocytochemical analysis of the BM cells of W/W^v mice treated with both mrGM-CSF and LPS showed that HDC was in the cytoplasm of cells having Mac-1, a macrophage-differentiation antigen. These results suggest that cells of the macrophage lineage in the BM of mice synthesize histamine.