ABSTRACT
Objective To investigate the effects of δ-opioid receptor agonist DADLE (D-Ala2-D-Leu5-enkephalin) on the hemodynamics and oxygen metabolism in rats with sepsis. Methods Eighty healthy male SD rats were randomly divided into 4 groups ( n = 20 each) : sham operation group (group S), sepsis group (group SEP) ,DADLE, group and DADLE2, group. Sepsis was induced by cecum ligation and puncture (CLP) in SEP, DADLE,and DADLE2 groups. In DADLE1 and DADLE2 groups, 0.5 mg/ml DADLE 10 mg/kg was injected intraperitoneally (IP) 0.5 h before CLP and immediately after CLP respectively. Mean arterial pressure (MAP), left ventricular systolic pressure (LVSP) and ± dp/dtmax were recorded at 0, 2, 4 and 6 h after CLP (T1-4). Blood samples from left common carotid artery and right external jugular vein were collected at T4 for blood gas analysis. The cardiac index (CI), O2 delivery (DO2), O2 consumption (VO2) and O2 extraction rate (ERO2) were calculated.Results Compared with group S, MAP and LVSP were significantly increased at T2, while decreased at T3,4, and ± dp/dtmax was significantly increased in group SEP, MAP was significantly increased at T2, while decreased at T3,4, LVSP was significantly increased at T2,3, while decreased at T4 , and ± dp/dtmax was significantly increased in DADLE, and DADLE2 groups, and CI, DO2 and VO2 were significantly decreased and ERO2 was increased in SEP, DADLE, and DADLE2 groups (P＜0.05). Compared with group SEP, MAP, LVSP and ± dp/dtmax at T3,4 and CI, DO2 and VO2 were significantly increased, while ERO2 was significantly decreased in DADLE1 and DADLE2 groups (P ＜ 0.05). There was no significant difference in the parameters mentioned above between DADLE1 and DADLE2 groups ( P ＞ 0.05). Conclusion δ-opioid receptor agonist DADLE can obviously improve the hemodynamics and oxygen metabolism in septic rats.
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.