AIM: Studying the mechanism of protective role of metallothionein (MT) in hypoxic preconditioning(HPC) of cultivated rat cardiomyocytes. METHODS: Using the model of hypoxia/reoxygenation of cultivated rat cardiomyocytes. Determing the contents of MT, malonyldialdehyde (MDA) - metabolism product of lipid peroxidation and the activities of Na+ - K+ ATPase, Ca2+ - Mg2+ ATPase of cardiomyocytes 24 h after HPC, the determining the relevant changes after using MT antibody. RESULTS: After 24 h in HPC, the contents of MT and activities of Na+ - K+ ATPase, Ca2+ - Mg2+ ATPase were obviously higher than those in the control and hypoxia/reoxygenation(P＜ 0. 05 ), and the contents of MDA were decreased remarkedly (P ＜ 0.01 ). Then after using MT antibody, the activities of two enzyme were progressively decreased and the contents of MDA were significanily higher than those in the control and MT antibody - free groups(P ＜ 0.01 ). CONCLUSION: HPC may induce excessive synthesis of MT, and MT can protect myocardial reoxygenation injury by eliminating lipid peroxidation and rising the activities of Na+ - K+ ATPase and Ca2+ - Mg2+ ATPase.

Objective To study the factors that influence the ex vivo proliferation of human immunodeficiency virus (HIV) specific CD8 T cells.Methods Three methods to use HIV-specific antigen peptides stimulating the proliferation of virus specific CD8 T cells from HIV patients were compared,and the effect of adding exogenous IL-2 into co-culture on proliferation was evaluated.Results In comparison to directly adding MHC I matched HIV peptides into peripheral blood mononuclear cells (PBMCs) by presence during co-culture or incubating for 2 hours,the more efficient proliferation of HIV-specific CD8 T cells was stimulated by loading HIV peptides on the mixed antigen presenting cells (APCs) that harvested by removing CD8 T cells from PBMCs.Adding IL-2 into co-culture could largely enhance the number of proliferated HIV-specific CD8 T cells but also induced non-specific proliferation of CD8 T cells.Conclusions Stimulation of HIV-specific CD8 T cells by loading HIV-specific antigen peptides on mixed APCs and in absence of IL-2 can specifically induce the efficient proliferation of HIV-specific CD8 T cells by providing both antigen and co-stimulation signals.