ABSTRACT
Objective To obtain Chinese hamsterovary (CHO) cell line expressing human decay accelerating activity (hDAF) stably and to observe the protective effect of hDAF on heterologous cells under the circumstance of complement activation. Methods The eukaryotic expression vector DAF pcDNA3.1 was constructed and then transfected into CHO cells by lipofection. Monoclones of cells expressing hDAF stably were screened by the method of limiting dilution. hDAF expression was detected by flow cytometry. The decay accelerating activity of hDAF was determined by assay of C3 deposition and 51Cr release. Results The expression vector DAF pcDNA3.1 was successfully constructed, and monoclones of cells expressing hDAF were obtained. CHO cells expressing hDAF could decrease C3 deposition and attenuate the killing effect of activation of the complement system. Conclusion We have obtained CHO cell clones expressing hDAF stably, which is helpful for the further studies of the relationship of the structure with the functions of hDAF.
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the effects of hypoxia on the glycolysis in cultured rat hepatocytes.</p><p><b>METHODS</b>Mixed gas with different concentrations of O(2), CO(2) and N(2) was prepared for the in vitro culture of normal rat hepatocytes. The cell strains were set to be A, B, C groups, which were observed at 1, 2, 4, 8 and 16 hours after hypoxia with normal hepatocytes as the control. Biochemical methods were employed to determine the activities of the key enzymes during hepatocytic glycolysis such as hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), lactate dehydrogenase (LDH) and the change of the content of lactic acid (LA) in the culture fluid.</p><p><b>RESULTS</b>(1) The LDH activity of the rat hepatocytes increased significantly at all the time points of hypoxia in A and B groups when compared with that in control group (P < 0.05), while the activity increased obviously in C group since 2 hours after hypoxia (P < 0.05). (2) The HK activity of the cells in A group increased significantly at 1, 2, 4 and 16 hours after hypoxia and that in B and C groups increased obviously at 1 hour when compared with control group (P < 0.05). While the cellular PFK activity in A group increased markedly at 1 and 4 hours after hypoxia and that in B and C groups increased evidently at 4 hours after hypoxia (P < 0.05). The cellular PK activity in all the three groups increased at all the hypoxic time points (P < 0.05). (3) The cellular LA content in A and B groups began to increase since 2 hours and that in C group did so since 4 hours after hypoxia and increased along with the time lapse (P < 0.05).</p><p><b>CONCLUSION</b>hypoxia might initiate glycolysis.</p>
Subject(s)
Animals , Rats , Cell Hypoxia , Cells, Cultured , Glycolysis , Hepatocytes , Metabolism , Hexokinase , Metabolism , L-Lactate Dehydrogenase , Metabolism , Lactic Acid , Metabolism , Oxygen , Metabolism , Phosphofructokinases , Metabolism , Pyruvate Kinase , MetabolismABSTRACT
Objective To establish an animal model of hepatic inflow occlusion with meso-caval shunt in Bama swines so as to evaluate the tolerance limit of normothermic hepatic inflow occlusion.Methods Eighteen Bama swines were divided into group A in which the hepatic blood inflow was occluded for 90 min and group B in which the hepatic blood inflow was blocked for 100 min.The animal survival rate,the changes of liver function and histopathology were observed.Results The animal survival rate was significantly higher in group A than group B(100% vs 44.4%,P