Effects of dexmedetomidine on cellular immune function of immunosuppression juvenile rats / 临床麻醉学杂志

ABSTRACT

Objective To explore the effects of dexmedetomidine on peripheral blood T lymphocyte proliferation and T lymphocyte subsets of juvenile rats with splenectomy.Methods Twenty-four healthy male Sprague-Dawley rats,weighing 130-150 g,aged six weeks were enrolled in this study.Half of the rats received splenectomy to make an immunosuppressive model,then they were randomly divided into 2 groups (n=6 each) splenectomy+normal saline group (group SN) and splenectomy+dexmedetomidine group(group SD).The another half of the rats without splenectomy were randomly divided into 2 groups normal saline group(group S) and dexmedetomidine group(group D).After one week of normal feeding,normal saline 10 ml/kg was injected intraperitoneally (ip) in groups S and SN,dexmedetomidine 50 μg/kg was injected ip in groups D and SD respectively.Two hours after the injection,blood samples were collected.MTT was utilized to examine the peripheral blood T lymphocyte proliferative capability.T lymphocyte subsets CD4+,CD8+ were determined by flow cytometry.CD4+/CD8+ was calculated.Results Compared with group S,T lymphocyte proliferative capability,the percentages CD4+,CD8+ and CD4+/CD8+ ratio were significantly decreased in group SN (P<0.05);T lymphocyte proliferative capability in group D was decreased (P<0.05),but no significant changes was found in the percentages CD4+,CD8+ and CD4+/CD8+ ratio.Compared with the group D,T lymphocyte proliferative capability,the percentages CD4+,CD8+ and CD4+/CD8+ ratio in group SD were significantly decreased (P<0.05).Compared with the group SN,T lymphocyte proliferative capability in group SD was significantly decreased (P<0.05).Conclusion Cellular immune function of juvenile rats with or without splenectomy is suppressed by dexmedetomidine,and the suppressive function is more severe in splenectomy rats than that in normal juvenile rats.