Growth and functional modifications in formaldehyde-treated mouse bone marrow-derived mast cells

The effects of formaldehyde on growth and differentiation of mouse bone marrow-derived mast cells (BMMC) were investigated in vitro. Mouse bone marrow cells (BMC) were cultured with 0.2, 0.4, 1.0 and 2.5 mug formaldehyde/ml for 3 wk in the presence of WEHI-3 conditioned medium. Both the number of total non-adherent cells and of alcian blue positive cells were affected at 2.5 mug formaldehyde/ml, but not at 1.0 mug formaldehyde/ml or below. Fluorescence intensity and histamine content in formaldehyde-treated (0.4 and 1.0 mug/ml) BMMC was significantly increased when compared with controls. However, IgE-mediated histamine release in BMMC cultured with formaldehyde showed no difference between formaldehyde-cultured and control BMMC. Histamine release, stimulated by 0.2 mug A23187/ml, from BMMC cultured with formaldehyde was increased. To examine the short-term effect of formaldehyde on normal BMMC, BMMC cultured for 3-5 wk were incubated with 1, 5 and 10 mug formaldehyde/ml for 30 min. Treatment with 5 or 10 mug formaldehyde/ml resulted in enhanced histamine release from BMMC stimulated with anti-mouse IgE or A23187. These results showed that BMMC cultures treated with formaldehyde had altered biochemical and functional properties.