The Experimental Study About Protective Effects Of Puerarin On Liver Of Brain-dead Rats

Purpose:We use improved progressive intracranial compression to set up brain death model in order to explore the possible mechanism on liver injury and the protective impacts of puerarin on the liver functions of rats under the state of brain death, describing the relevant evidences for better utilizing brain death donor in the daily clinical work.Method:divided 60 adult male SD rats (weight:350-400g) into 3 groups randomly. The group of control (Group c)20, continuous anesthesia, only give craniotomy, while placing intracranial Fogarty 3F balloon catheter, without setting up the model of brain death. Group B: the group of brain death,20,use improved progressive intracranial compression to set up brain death, preserve the state of brain death for 4 h through respiratory and circulatory support; Group N, the group of puerarin,20,using the method which is same as group B to setup and confirm the model of brain death successfully, then give puerarin at the dose of 50mg/kg,preserve the state of brain death for 4h.Make the surveillance on the change of MAP before intracranial compression, in-progress and after brain death.4h after brain death, collect the blood sample through vena cava. after 30 minutes' quiescence and centrifugation, retain the serum to test the serum ALT,AST through automatic biochemical analyzer, measuring the expression of TNF-a through ELISA, under the method of xanthine oxidase to test the activity of SOD in the liver tissue. After collecting the blood sample, deal with the liver sample under the process of embedding, section and HE staining to observe the morphological changes. Using the system of SPSS 6.0 to cope with the data and the results are shown in the form of (x±s).Using factor analysis of variance and multiple-group t test to statistical treatment, definite P<0.05 is the bound of significant difference.Results:(1)the change of MAP:before intracranial compression, there's no significant difference between experimental group and control group(P>0.05).During the process of compression gradually, obvious changes have taken place in the group B and N, compared with group C, there're significant differences(P<0.05).After the state of brain death, the MAP of group B and N have a sharp drop compared with the normal state, but there are no significant differences between the two groups(P>0.05). The MAP of group C has no change during the whole experimental process.(2)The changes of serum ALT,AST, IL-6 and TNF-a:Group B is higher than group N and C (P<0.05), ALT and AST of group N is much lower than group B but higher than group C (P<0.05), there are significant differences.(3)The activity of SOD in the liver tissue:group B is much lower than group N and c, there are significant differences (P<0.05); Group N is much lower than group C but much higher than group B, there are significant differences (P<0.05).(4)The morphological changes in liver:group C:the morphological structure of liver is normal. HE staining shows the uniform rendering of liver tissue. There are no pathological changes such as necrosis, edema, ect. Group B:disorganization, crumbly cytoplasm can be seen. The volume of hepatocyte has increased, the boundary of which is obscure as well. Obvious vacuolar degeneration can be found in some hepatocytes. Group N:the structure of liver cells is normal generally, there are some mild edemas and vacuolar degeneration in some liver cells, lighter than group B.Conclusion:1.Using progressive intracranial compression to set up the model of brain death can better simulate the clinical process of brain death.2. The hemodynamic changes under the state of brain death, disorder of endocrine system and the abundant emission of inflammatory factors can induce the damage of liver function and structural changes of liver.3. The elevation of serum TNF-a and the reduction of the activity of SOD in the liver tissue maybe one of important reasons of leading the damage of liver under the state of brain death.4. After brain death, using puerarin to pretreat can relieve the damage of liver function under the state of brain death to some extent. The possible mechanism may be related to better micro-circulation of liver, high activity of SOD, elimination of oxygen free radical during the process of brain death, suppression of the emission of inflammatory factors.