The Protective Effect And Mechanism Of Hydrogen-Rich Saline Against Acute Brain Injury After Orthotopic Liver Transplantation Of Rats

Objective Good blood circulation can maintain normal metabolism and function of the body. Ischemia of local tissue and organs caused by various reasons, it often makes ischemia injury.But through animal experiments and clinical observation,it also found that after blood reperfusion under certain conditions, some animals or patients with functional metabolic disorders and structural damage got worse injury.Therefore,we call this ischemia- reperfusion injury. In recent years, with the large-scale development of liver transplantation, more and more people pay more attention to the protection of all organs. Because of ischemia and reperfusion, different organs are faced to different degrees of damage, which affects the long-term survival rate of patients with liver transplantation. The mechanism of ischemia-reperfusion injury is related to oxidative stress and apoptosis. In this study, we evaluated the protective effect of hydrogen-rich saline against acute brain injury after orthotopic liver transplantation in rats.Methods 56 healthy adult male SD rats, 8~10 weeks, weighing 220~250g, were divided into 4 groups randomly, 8 rats in each group(n=8): sham operation group(group S), liver transplantation group(group OLT), hydrogen-rich saline treatment group(group HS) and chloroquine pretreatment group(group CQ). In group S, the rats performed simple laparotomy, and isolated the related blood vessels. In group OLT, the rats underwent the orthotopic liver transplantation, and were slowly injected saline at a dose of 6ml/kg 5 minutes before anhepatic phase into the inferior vena cava. In group HS, the rats were slowly injected hydrogen-rich saline at a dose of 6ml/kg 5 minutes before anhepatic phase into the inferior vena cava, other operations were same to group OLT. In group CQ, chloroquine was injected intraperitoneally at a dose of 60mg/kg an hour before surgery, other operations were same to group HS. After 6 hours of reperfusion, we observed the histological index to confirm the situation of brain injury. Apoptosis of cells was detected by TUNEL staining. The levels of autophagy and apoptosis relative proteins were assayed by western blot analysis.Results Compared with group S, the level of oxidative stress in brain tissue of group OLT increased, apoptosis of cells increased significantly, the expression level of caspase-3 and cyt c were up-regulated. Whereas, the level of oxidative stress and apoptosis and the expression level of caspase-3 and cyt c of group HS were reduced significantly. At the same time, the expression of p53, LC3?and beclin-1 were up-regulated. Group CQ used chloroquine to partly inhibit the protective effect of hydrogen. The apoptotic index of group OLT, group HS and group CQ was significantly higher than that of group S, the apoptosis index of group OLT was higher than that of group S, and the apoptosis index of group CQ was significantly higher than that of group HS.Conclusion As a reducing agent,hydrogen has the characteristics of anti-oxidation and anti apoptosis. The key to the protection of hydrogen is to neutralize free radicals. Hydrogen can selectively scavenging hydroxyl radical(?OH) and peroxynitrite(ONOO?), but not reaction with the other physiological functional active oxygen free radicals. In this study, the rats were slowly injected hydrogen-rich saline at a dose of 6ml/kg 5 minutes before anhepatic phase into the inferior vena cava, the results shown that the MDA of brain tissue decreased, while the activity of SOD was increased, and the pathological changes of brain tissue in rats were significantly improved,indicating that hydrogen can relieve the oxidative injury after live transplantation in rats.The results shown that the level of p53 was significantly up-regulated by saturated hydrogen treatment, and the expression of LC3?and beclin-1 was significantly increased, and the expression of caspase-3 and cyt c was significantly down- regulated. Hydrogen-rich saline can activate the expression of p53 by inducing autophagy. As a result, it can protect brain tissue against injury after orthotopic liver transplantation.