The Effect Of Etomidate On Apoptosis And Cytotoxicity Of Humen Peripheral Blood Mononuclear Cells

Background:With the development of anesthesiology and surgery ,the survival rate of patients with malignant tumor have remarkly improved,and the research on perioperative tumor immunity has become a focus.Natural killer cell is a important part of tumor immunity,which can kill tumor cell directly. Moreover,more evidences suggested natural killer cells can aggregate in the position of tumor including protopathic and metastatic focus ,and can kill metastatic tumor cells so as to prevent tumor dissemin- ateion.What is more , it is Also discovered through further research that,besides the spontaneous anti-tumor function, the NK cell has also greatly strengthened immunology adjustment function.With regard to influence of anaesthesia and the anaesthetics on tumor immunity of the tumor patient in the perioperitive period, most literature has been focusing on the quantity of T lymphocyte subgroup and the NK cell.Results sugge- sted that the quantity of T cell subgroup as well as the NK cell remarkably reduces and T cell subgroup imbalance coexists. But few people further discuss the reason of quantity reduces and the NK cell function.As one of the most commonly used intravenous anesthe- tics, Etomida- te features in its quick efficacy as well as minute side effect on hemodyna- mics. It is discovered through clinical studies that the long-term application of Etomidate has caused immunosuppression and increasing mortality rate,which was considered to have been induced by dysfunction of adrenal co- rtex. It's still unknown whether the immunodepression is caused by directly suppressing certain elemens in immune system or indirectly caused by sup- pressing adrenal cortex by Etomidate due to the complex internal environment.Objective: To investigate the effect of etomidate on apoptosis andcytotoxicity of human peripheral blood mononuclear cells in vitro.Methods: Peripheral venous blood samples were collected from six healthy volunteers. The mononuclear cells were separ- ated by density gradient centrifugation after the blood sample had been layered on Lympholyte-H solution and then cultured in vitro immediately with tissue culture medium RPMI-1640, The mononuclear cells was divided into four groups:the contact group and three etomidate groups(E1,E2 and E3) , The final con- centration of etomidate in each group was 0.5,5 and 50μg/ml respectively. After 24 hours , level of apoptosis was assessed by flow cytometry with Annexin-V/PI as fluorescent marker . To determine cyto- toxicity, MTT chromatometry was measured by mixing mononuclear cells with K-562 tumor cells as target cells.Results: Cytotoxicity and apoptosis of etomidate-treated mononuclear cells were unchanged under concentrations of 0.5,5ug/ml. However, signif- icant differences were observed in cytotoxicity and apoptosis with etomidate 50 ug/mL. Conclution: In clinical situation, etomidate does not alter the extents of apoptosis and cytotoxicity of mononuclear cells in vitro.