| Objective:1.Anoxia/reoxygenation injury of myocardial cells is injured by many factors,the concrete machanism is not very clear.This study is to investigate the effect of the oxygen free radical in myocardial cells in rats ofanoxia/reoxygenation.2. Some researches show that the inflammatory cyokine has a hand in anoxia/reoxygenation injury of myocardium.This article through having observed the express of inflammatory cyokine of interleukin-1 β (IL-1β ) and tumor necrosis factor- α (TNF- α ) after anoxia and reoxygenation injury to indicate the function of IL-1 β and TNF- α in myocardial cells of anoxia/reoxygenation.3. Reduced Glutathione(GSH) is a substance which can eliminate the free radical.This study is to find out the protective effect of GSH on anoxia/ reoxygenation injury of myocardial cells in rats.Methods: 1 to 3 days old rats were used. The ventrical tissue of the hearts were selected.The specimen was cutted into pieces of 0.5 to 1mm3.Digesting 4 to 5 times with 0.25% pancreatin.All the supernatant solution except the first digesting solution was clectted,that was centrifuged 10 minutes at 4℃ , 500 r/min, then the supernatant was discarded. The remain cells, after had washed with balanced salt solution, were mixed to suspension with DMEM culturd midium, and were purificated to keep the myocardialcells out of others. Primary cultured myocardial cells of rats were randomly allocated to 5 groups:control group just used normal saline; reduced glutathione groups were respectively given 0,40,80,160mg/L medicament before anoxia(2h) or reoxygenation(lh). Measuring the activity of superoxide dismutase(SOD) and the level of malondiadehyde(MDA) before anoxia, 2 hours after anoxia and 1 hour after reoxygenation on each group. While measuring IL-1β mRNA and TNF- α mRNA before anoxia and 1 hour after reoxygenation by RT-PCR on control , singleanoxia/reoxygenation group and 160mg/L GSH group.Results: 1.After anoxia and reoxygenation, cardiomyocytes contracted, tending to get round in shaoe and its pseudopods decreased. Most cardiomyocytes were not beating. As the increasing of the dosage of GSH,the change of cells were improved.2. In single anoxia/ reoxygenation group(0mg/L), the activity of SOD was decreased, while MDA was increased after anoxia or reoxygenation.Compared to 2 hours after anoxia ,the changes of the activity of SOD and MDA were more markedly with the content of cellular IL-1βmRNA and TNF- α mRNA be increasing(P<0.01).3. Giving reduced glutathione could significantly attenuate the reduced SOD activity and the elevated MDA,IL-1βmRNA and TNF- α mRNA level(P< 0.05).The protective on MDA in a dose-dependent manner and 160mg/L on SOD showed the greatest protective effect(P<0.01), approaching to control group(P>0.05).Conclusion: 1.In the mechanism of the injury to cardiomyocytes by anoxia/reoxygenation,the free radical is one of the most important factors.2. The inflammatory cyokines of IL-1β and TNF-α take part in the injury to cardiomyocytes by anoxia/reoxygenation,they may play a negative synergism role.3.Glutathione could protect the myocardial cell from the injury by anoxia/ reoxygenation.That may be related to the ability of glutathioneagainst the oxidant injury. Glutathione can reduce the increasing of IL-1βmRNA and TNF- α mRNA. There are effected each other of inflammatory cyokine and the oxygen free radical in the mechanism.
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