The Study Of The Profective Effect Of Reduced Glutathione On Anoxia/Reoxygenation Injury Of Cultured Myocardial Cells In Rats

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 over-load of cytosplic free Ca²⁺ has a hand in anoxia/reoxygenation injury of myocardium.This article through having observed the change of cytosplic free Ca²⁺ after anoxia and reoxygenation injury to indicate the function of over-load of cytosplic free Ca²⁺ in myocardial cells of anoxia/reoxygenation.3. Reduced Glutathione(GSH) is a substance which can eliminate the free radical and perhaps can be regarded as an calcium antagoni.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 centrifuged10 minutes at 4"C , 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 myocardial cells out of others. Primary cultured myocardial cells of rats were randomly allocated to 5 groupsxontrol group just used normal saline;reduced glutathione groups were respectively given 0,80,160mg/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 the cytosolic free Ca2+on 1 hour after reoxygenati .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 on 1 hour after reoxygenati.The modle of group successfully brings about the over-load of cytosolic free Ca2+.The content of cytosolic free Ca2+ be increasing on 1 hour after reoxygenation (P<0.01).3. Giving reduced glutathione could significantly attenuate the reduced SOD activity and the elevated MDA, cytosolic free Ca2+ (P< 0.01).The protective onSOD, MDA ,cytosolic free Ca2+ in a dose-dependent manner and 160mg/L on SOD , cytosolic free Ca2+ showed the greatest protective effect(?<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 over-load of cytosolic free Ca2+ take part in the injury to cardiomyocytes by anoxia/reoxygenation,they may play a negative synergismrole.3.Glutathione could protect the myocardial cell from the injury by anoxia/ reoxygenation.That may be related to the ability of glutathione against the oxidant injury and inhibit calcium overload. Glutathione perhaps can be regarded as an clciumantagonis.