The effect of oxidative stress induced by different concentrations of hydro
gen peroxide on dog neutrophils was studied. This effect was measured using
dichlorofluorescein-diacetate (DCFH-DA) and by the cell surface membrane e
xpression of heat shock protein (HSP) 27 kDa, HSP 72 kDa and HSP 90 kDa fam
ilies. Hydrogen peroxide induced a concentration-dependent increase in DCFH
oxidation (from 10(-6) M to 10(-4) M), and an increase in the cell surface
expression of HSPs families. At a concentration of 10-4 hi, the percentage
of positive cells that showed an oxidation of DCFH was 94.7% +/- 5.2 (n =
3). Only vitamin E (but not vitamin C) at a concentration of 0.5 mM was abl
e to inhibit the intracellular oxidative stress induced by hydrogen peroxid
e. The percentage of positive cells that express these proteins after the t
reatment with hydrogen peroxide (10-4 M) was: 74% +/- 3.5 for HSP 27, 72% /- 2.6 for HSP 72 and 73% +/- 1.2 for HSP 90 (n = 3). This cell surface exp
ression was not abolished by either vitamin C or vitamin E. Localization of
HSPs in plasma membrane is of immunological interest because they have bee
n implicated in autoimmune diseases. (C) 1999 Elsevier Science Ltd. All rig
hts reserved.