AJP - Lung Cellular and Molecular Physiology, Vol 267, Issue 1 85-L93, Copyright © 1994 by American Physiological Society
Hydrogen peroxide effects on rat mast cell function
D. B. Peden, L. Dailey, W. DeGraff, J. B. Mitchell, J. G. Lee, M. A. Kaliner and R. J. Hohman
Department of Pediatrics, School of Medicine, University of North Carolina at Chapel Hill 27599.
Oxidant exposure of the airway mucosa may play a significant role in the
pathophysiology of asthma and allergic rhinitis. Mast cells play an
important role in asthma, and oxidant exposure has been reported to cause
direct mast cell degranulation as well as augment immunoglobulin E
(IgE)-mediated responses in vivo. H2O2 is an oxidant generated by
inflammatory cells and by the interaction of ozone with lipids or aqueous
solutions. In this study, the RBL-2H3 mast cell line was used to
investigate the ability of H2O2 to induce mast cell responses as well as to
effect mast cell responses to IgE and the calcium ionophore A23187.
Although cytotoxicity of RBL-2H3 cells at the membrane level was not
observed with any concentration of H2O2, DNA damage resulted from exposure
to 0.2 and 2.0 mM H2O2, and cell proliferation was inhibited by 0.075-0.2
mM H2O2. RBL cell prostaglandin D2 generation was enhanced after 60- and
120-min exposure to 0.2-20 mM H2O2. Direct serotonin release required
120-min exposures to 2.0 mM and 60-min exposures to 20 mM H2O2. However,
degranulation responses induced by either IgE or A23178 were diminished
after exposure to 0.2-2.0 mM H2O2. Lesser amounts (0.005-0.02 mM) had no
effect on mast cell function. In summary, H2O2-induced responses of RBL
cells, as well as modification of responses to IgE and A23187, occurred
only at high concentrations of H2O2, which also induced both intracellular
damage and inhibition of cell proliferation. Concentrations of H2O2 more
likely to be physiologically relevant had no effect on mast cell responses
or cytotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)
