Experimental observation of the changes in immune indices of lymphocytes and lymphocytes with hypoxia preconditioning cultured in low O_2 tank

Objective To investigate the effect of hypoxia preconditioning on changes of immune indices and proliferation of lymphocytes cultured in low O 2 tank. Methods Lyphocytes were separated from peripheral venous blood of healthy personnel by Ficoll-Hypaque density gradient centrifugation method. The lymphocyte specimens were divided into 3 groups: normal control group (NC), acutehypoxia group (AH) and hypoxia preconditioning group (HP). The later 2 groups underwent acutehypoxia in a low oxygen tank (1%O 2, 5%CO 2) for 2 h, and HP group experienced intermittent hypoxia(3%O 2, 5%CO 2) for 2 h for 6 times before the acute hypoxia exposure. Lymphocytes [Ca 2+]i was assayed by Fura-2/AM fluorescence method, the levels of IgG and IL-2 in the media were determinedby ELISA method and lymphocyte transformation rate was measured by MTT method. Results In AH group, lymphocyte [Ca 2+]i, lymphocyte IgG and IL-2 secretion levels, as well as lymphocyte transformation rate were lowered significantly (P0.01) as compared with NC group, while in HP group, all these changes as compared with NC group were non-significant. Conclusions The results suggest that the immune function of lymphocytes was lowered after acute hypoxia exposure, and hypoxia preconditioning can alleviate the change effectively, in which the adaptive change of [Ca 2+]i may play an important role.