[Establishment and evaluation of oxidative stress injury model of in vitro rat aortic endothelial cells].

OBJECTIVE: To establish a model of oxidative stress injury in cultured rat aortic endothelial cells, and to provide a basis for the research of cell injury and apoptosis. METHODS: The rats were decapitated to get the aorta in thoracic operation under aseptic conditions. By subculture after tissue block culture method to get sufficient aortic endothelial cells, cultured in 96-well plates or grow on cover glass for the following test. Without H2O2 group as a control group, with different doses of H2O2 (100,200,300,400,500 µmol/L) treated endothelialcells in 12 h to screen the optimal dose. Based on the results, with the same dose of H2O2 (100 or 200 µmol/L) acted on endothelial cells respectively in different time (3, 6, 9, 12 and 24 h) to screen the optimal duration. Each group was made in sextuplicate. The establishment of the model was evaluated by immunofluorescence,cell viability testing, biochemical indicators detection (lactate dehydrogenase(LDH), nitric oxide(NO), malondialdehyde(MDA), superoxidedismutase(SOD))and apoptosis index testing. RESULTS: Endothelial cells were cultured successfully and verified by immunofluorescence staining of intracellular antigen Ⅷ collagen. With the increase of H2O2 doses at the same action time 12 h, the cell viability was significantly decreased (77.63%±5.20% to 40.90%±2.10%). The same dose(100 µmol/L group and 200 µmol/L group)with the action time increasing, the cellviability was significantly decreased (100 µmol/L group was 86.83%±12.11% to 44.26%±5.70%, 200 µmol/L group was 78.28%±11.98% to 34.45%±5.87%). At dose of H2O2 was 100 µmol/L and treated in 3,6,9,12 and 24 h, LDH-L and MDA were significantly increased after 9 h while NO and SOD were significantly decreased. In H2O2 dose of 100 µmol/L and action time 12 h, flow cytometry showed endothelial cellapoptosis rate was 16.92%±2.37%, significantly higher than the control group of 2.68%±0.47%(P<0.01); TUNEL detected endothelial cell apoptosis index was17.65%±2.36%, which was significantly higher than that in the control group of 3.23%±0.57%(P<0.01). CONCLUSIONS: The method was successfullyestablished a model of oxidative stress injury in cultured rat aortic endothelial cells, explore the moderate conditions that induced cells injury and apoptosis which could be a basis for the research.

[Protective effects of histone deacetylase inhibitor on stress-induced myocardial injury in rats].

OBJECTIVE: To observe the protective effects of histone deacetylase inhibitor on stress-induced myocardial injury. METHODS: Healthy male Wistar rats were randomly divided into 3 groups( n = 6), and the stress-induced myocardial injury model was established with chronic restraint stress method. The protective effects of histone deacetylase inhibitor on stress-induced myocardial injury were observed with Trichostatin A (TSA) intervention. Histone acetylation levels in myocardium of rats were detected by Western blot method, spectrophotometry method was used to dynamically determine the activity of rat serum lactate dehydrogenase (LDH), serum creatine kinase isoenzyme-MB (CK-MB) and Caspase 3, and nagar Olsen staining were used to observe the early myocardial damage. RESULTS: Restraint stress could significantly reduce the level of histone acetylation of myocardium in rats, and TSA intervention could inhibit the stress-induced reduction of myocardial levels of histone acetylation. Restraint stress could cause the significant increase of serum LDH activity ( P < 0.05), serum CK-MB activity ( P < 0.05), and the Caspase 3 activity of myocardial tissue (P < 0.05), and early myocardial damage also occurred during restraint stress. ISA intervention could significantly reduce the serum LDH activity (P < 0.05), the serum CK-MB activity (P < 0.05), the activity of myocardial tissue caspase 3 induced by restraint stress (P < 0.05), and the stress-induced myocardial injury was also attenuated by TSA intervention. CONCLUSION: The histone deacetylase inhibitor TSA can protect stress-induced myocardial injury.