OBJECTIVETo investigate the changes in cellular apoptosis of Peyer's patches in severely scalded mice, and to explore its role in the pathogenesis of gut barrier damage.

METHODSForty BALB/c mice were randomly divided into normal control, 12 post-scald hour (12PSH), 24PSH and 72PSH groups, with 10 in each group. The mice in all PSH groups were inflicted with 20% TBSA full-thickness scald on the back. The mice in all the groups were sacrificed at different time points, and Peyer's patches were harvested from all the mice for HE staining, DNA gel electrophoresis, and flow cytometry ( FCM) examination with FITC conjugated Annexin-v and propidium iodide( PI) staining of cells.

RESULTSHE staining revealed that there were relatively abundant apoptotic cells scattering in Peyer's patches of scalded mice . DNA electrophoresis of Peyer's patches revealed typical " ladder" pattern at all indicated time points in scalded mice. Apoptotic percentage of detached Peyer's patches cells in control and scalded group were (4. 9+/-2. 1)% , (26.7+/-3. 1)% , (21.6 +/-4.0)% ,(12. 8 +/-2.0)% , respectively, and the percentage reached the peak at 12 PSH.

CONCLUSIONApoptosis is a principle modality of cell death of small intestinal Peyer's patches lymphocytes in severely scalded mice, and it might contribute to immunity barrier failure of intestinal wall after severe thermal injury.