[Change in apoptosis rate and expression of apoptosis-related gene of lamina propria lymphocyte and intra-epithelial lymphocyte after burn and delayed resuscitation].

OBJECTIVE: To study the effects of delayed resuscitation on the apoptosis rate (ap%) and expression of apoptosis-related genes of lamina propria lymphocytes (LPL), intra-epithelial lymphocyte(IEL) after burn in rats. METHODS: Thirty Wistar rats were randomly divided into early resuscitation (ER) and delayed resuscitation (DR) groups, 24 rats of them were subjected to 30% total body surface area (TBSA) III degree scald burn on back, among which 12 received fluid resuscitation immediately, and 12 with delayed fluid resuscitation. Six rats were subjected to sham burn served as control. DNA fragmentation, DNA agarose gel electrophoresis were used to observe the apoptosis of LPL and IEL. Reverse transcription-polymerase chain reaction (RT-PCR) was employed to detect the expression of interleukin-1beta-converting enzyme (ICE) and B cell lymphoma-2 (bcl-2). RESULTS: The ap% of LPL and IEL increased significantly after burn (all P<0.01). The ap% in DR group was higher than in ER group at 12 hours postburn. Distinct DNA "ladders" were visualized in agarose gel electrophoresis 6 hours postburn for both LPL and IEL. The expression of ICE gene increased dramatically after burn, and it expressed higher in DR group than that in ER group postburn (P<0.05 or P<0.01). A strong expression of bcl-2 in LPL and IEL were detected before burn, but the expressions decreased significantly after burn and delayed resuscitation (P<0.05 or P<0.01). CONCLUSION: The apoptosis of LPL and IEL increased significantly after burn and delayed resuscitation. The unbalanced expression of apoptosis-enhanced gene ICE and apoptosis-inhibited gene bcl-2 may be responsible for the dramatically increased apoptosis of LPL and IEL postburn.