Role of β-endorphin in the suppression of cellular immunity of rats following trauma-hemorrhagic shock()

AIM: To explore the role of plasma β-endorphin(β-EP) in the suppression of cellular immunity following trauma-hemorrhagic shock(T-HS). METHODS: ① Wistar rats with T-HS were sacrificed at 0 h, 1 h, 3 h, 6 h, 12 h, 24 h after T-HS. Plasma sample was collected and β-EP levels in plasma was measured. Rats with sham-operated were served as the controls. ②In in vitro experiment, splenic cells were isolated and mixed from four normal rats and cocultured with shock plasma (SP) or SP +β-EP antiserum. ConA-induced splenic cell proliferation, IL-2 production, IL-2R expression were examined. RESULTS: ① Levels of plasma β-EP elevated remarkably after T-HS immediately, peaked at 1h , showed decreasing tendency and restored normal 24 h after T-HS. ② Shock plasma significantly suppressed ConA-induced splenic cell function. Levels of plasma β-EP were negatively correlated with spenic cell proliferation and IL-2 production and IL-2R expression. Compared with SP group, splenic cell function elevated markedly in SP + β-EP antiserum group, but still lower than that in controls. CONCLUSION: The elevated plasma β-EP following T-HS was involved in the suppression of cellular immunity.