[The influence of hypoxia inducible factor-1 alpha expression on apoptosis and proliferation of T lymphocyte in the Peyer's patches after burn with delayed fluid resuscitation in rats at high altitude].

OBJECTIVE: To explore the influence of hypoxia inducible factor-1 alpha (HIF-1 alpha) expression on the apoptosis and proliferation of T lymphocyte after severe burn with delayed fluid resuscitation at different altitude in rats.

METHODS: One hundred and thirty-two Wistar rats were subjected to burn injury [30% total body surface area (TBSA), III degree], at 1,517 metres and 3,848 metres above sea level, and they were randomly divided into three groups: delayed fluid resuscitation group (DFR, n=30 at each altitude), immediate fluid resuscitation group (IFR, n=30 at each altitude), and sham group (SG, n=6). The Peyer's patches were harvested from the ileum of rats at 6, 12, 24, 48 and 72 hours after burn respectively. The levels of HIF-1 alpha, CD3(+) and the rate of apoptosis in Peyer's patches were detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), tissue microarray technology and immunohistochemistry.

RESULTS: The apoptosis rate in Peyer's patches was higher in DFR group than that in IFR group. The increase in HIF-1 alpha expression was observed mainly on cell nucleus in T lymphocytes. The expression levels of HIF-1 alpha in Peyer's patches were much higher in DFR group and IFR group than those in SG, and they were higher at 3 848 metres than those at 1 517 metres, and also higher in DFR group compared with IFR group (all P<0.05). The decrease in CD3(+) expression was observed mainly on cell membrane in T lymphocytes. The expression levels of CD3(+) in Peyer's patches were much higher in DFR group and IFR group than those in SG group, and the trough value appeared at 12 hours after burn (all P<0.05).

CONCLUSION: High expression of HIF-1 alpha may be responsible for the high apoptosis rate and decrease of T lymphocyte number in Peyer's patches after severe burn with delayed fluid resuscitation in rats at high altitude.