Objective To observe the effect of ischemic postconditioning on myocyte apoptosis in hyperlipemia rats with myocardial ischemic reperfusion.Methods Total forty-eight hyperlipemia SD rats were randomly divided into the sham-operation group, ischemic reperfusion group and ischemic postconditioning group with 16 rats in each group. The myocardial ischemic reperfusion model of rat was made. Rats in the ischemic reperfusion group were ligated for 40 min ischemia, and then reperfused for 240 min. Rats in the ischemic postconditioning group were treated for 40 min ischemia, reperfused for 10 s and 10 s ischemia for three cycles, and then reperfused for 240 min. Rats in the sham-operation group were opened the chest to braid for ringer without deligation. The presence of apoptotic myocytes was detected by the method of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL). Meanwhile, the serum creatine kinase activity and myocardial infarct size were measured.Results The creatine kinase activity was 734.86±25.48 U/L in the ischemic postconditioning group and 967.64±28.16 U/L in the ischemic reperfusion group after reperfusion, all significantly higher than that (274.28±16.94 U/L) in the sham-operation group ( P<0.05), and it was significantly lower in the ischemic postconditioning group than that in the ischemic reperfusion group ( P<0.05). There was no significant difference in ratio of myocardial ischemic size and left ventricle after reperfusion between the ischemic postconditioning group and the ischemic reperfusion group. But the ratio of myocardial necrotic size and ischemic size of the ischemic postconditioning group was 24.8%±6.7% and significantly lower than that (38.2%±7.1%) of the ischemic reperfusion group ( P<0.05). No apoptotic myocardial cells were found after the reperfusion in the sham-operation group. The apoptotic rate in the ischemic postconditioning group (12.7%±2.8%) was significantly lower than that (20.9%±3.7%) in the ischemic reperfusion group ( P<0.05).Conclusion Ischemic postconditioning can relieve the ischemic reperfusion injury in hyperlipemia rats, the mechanism of which may be related with decreased myocardial apoptosis.

AIM: To observe the effects of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), myeloperoxidase (MPO) and transforming growth factor-β1 (TGF-β1) of radiation-induced lung injury rats by Kiwi fruit essence (unsaturated fatty acid of actinidia chinesis planch seed oil). METHODS: According to random number table, 90 Sprague-Dawley rats were divided into the control group, model group, 60 mg/kg unsaturated fatty acid of actinidia chinesis planch seed oil intervention group, 120 mg/kg unsaturated fatty acid of actinidia chinesis planch seed oil intervention group, 240 mg/kg unsaturated fatty acid of actinidia chinesis planch seed oil intervention group, 18 animals were included in each group. Except for the control group, rats in the remaining groups were constructed by 6MV-X-ray 18Gy full chest radiation, one week before modeling, the rats in the last 3 groups were given (60, 120, 240) mg/kg unsaturated fatty acid of actinidia chinesis planch seed oil. The first two groups were given 0.9% sodium chloride solution by gavage, once a day in each rat. 14 days, 28 days, and 56 days after radiation, the rats were randomly sacrificed and their chests were cut, and ave lung tissue was saved. HE and Masson staining were performed to observe the pathological changes, and the content of SOD, GSH-Px, MPO was determined. The expression of TGF-β1 was analyzed by immunohistochemical staining. RESULTS: Compared with the model group, (60, 120, 240) mg/kg unsaturated fatty acid of actinidia chinesis planch seed oil significantly reduced the degree of lung alveolitis and radiation pulmonary fibrosis, reduced the content of hydroxyproline (HYP), MPO, increased the antioxidant enzymes SOD and GSH-Px content, down-regulated the expression of TGF-β1.There were significant differences in the above-mentioned indicators among the intervention groups of (60, 120, 240) mg/kg unsaturated fatty acid of actinidia chinesis planch seed oil group, and it was positively correlated with dosage. CONCLUSION: Unsaturated fatty acid of actinidia chinesis planch seed oil has a preventive effect on radiation-induced lung injury, and its mechanism may be related to the reduction of oxidative stress damage and down-regulation of TGF-β1 expression.