ABSTRACT
Objective To investigate the effect of δ-opioid receptor agonist D-Ala2-D-Leu5-enkephalin (DADLE) on the celluar immune function in septic rats. Methods One hundred and fifty healthy male SD rats weighing 154-198 g were randomly divided into 3 groups (n = 50 each):group Ⅰ sham operation (group S);group Ⅱ sepsis (group SEP) and group Ⅲ DADLE. Sepsis was induced by cecum ligation and punture (CLP) in group Ⅱ and Ⅲ. In group Ⅲ 0.5 rmg/kg DADLE 10 ml/kg was injected intraperitoneally (IP) immediately after CLP operation. Seven day survival rate was calculated. Blood samples were collected from 10 animals at 4, 8 and 12 h after operation (T1-3) respectively in each group for determination of serum TNF-α and IL-10 concentrations by ELISA and changes in T-cell subsets by flow cytometry. Results CLP significantly increased serum TNF-α and IL-10 concentrations and TNF-α/IL-10 ratio at T1-3 and decreased CD4+ and CD4+/CD8+ ratio and increased CD8+ at T3 in group Ⅱ as compared with group S (group Ⅰ). DADLE treatment significantly attenuated the CLP-induced above changes. Seven-day survival rate was significantly higher in DADLE group than in CLP group.Conclusion δ-opioid receptor agonist DADLE can improve the celluar immune function of rats with sepsis and increase the survival rate.