ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of dexamethasone on spontaneously apoptosis, bcl-2, and neuclear facor kappa (NFkappaB) expressions of polymorphonuclear neutrophil (PMN) from postburn rabbits.</p><p><b>METHODS</b>PMN were isolated from 8 rabbits on 24 postburn hours and cultured with normal serum (NS), burn serum (BS), normal serum plus dexamethasone (ND), and burn serum plus dexamethasone (BD) for 24 hours, respectively. The quantification of apoptosis was analyzed by acridine orange + ethidium bromide fluorescent staining and flow cytometry , and the contents of bcl-2 and NFkappaB protein detected by immunohistochemical method.</p><p><b>RESULTS</b>In the BS group, the percentage of apoptotic PMN decreased (compared with NS group, 6.18 +/- 0.96 vs. 21.77 +/- 2.32, P<0.05), and the contents of bcl-2 and NFkappaB protein increased (compared with NS group, 83.27 +/- 5.45 vs. 49.95 +/- 2.67, P<0.05). When compared with BS group, the apoptotic percentage of BD group increased (12.67 +/- 0.71 vs. 6.18 +/- 0.96, P<0.05), and the content of NFkappaB protein reduced (0. 1031 +/- 0.0154 vs. 0.1802 +/- 0.0130, P<0.05), but no significant difference between ND and NS group was found.</p><p><b>CONCLUSION</b>Dexamethasone decreases the inhibition of PMN apoptosis by bumn serum, which may be associated with the down-regulation of NFKB expression.</p>