| Objective: To study (1) the role and relation of hepacyte apoptosis and oxidativestress in the experimental FLD, (2)to study the effects of both fat-rich diet and alcoholto the rats'liver; to establish the basis for study the pathogenesis of FLD.Materials and Methods:Forty-six male Wistar rats were divided into four groups randomly: controlgroup(11); alcohol group(12); fat-rich diet group(11); alcohol and fat-rich dietgroup(12). FLD rat model was made by feeding alcohol of increasing concentrationgradually(30%,40%,50%;4.8,6.4,8g/kg/day, respectively), intragastrically or fat-richdiet or both on the basis of standard diet. All rats were sacrificed by femoral arterybleeding at the end of the 16th week from the feeding days, and the following wasmeasured: body weight, liver index(liver body and weightratio); AST,ALT,CHO,TG,FFA in serum; SOD,GSH,MDA in hepatic tissue; theexpression of caspase-3 mRNA in hepatic by RT-PCR and caspase-3 in hepaticspeciments by immunohistochemistry, HE dye and ultrastructural observation.Results:1. Rats weight and liver index: Rats in F group were significantly higher than othergroups(P＜0.05), and there wasn't significant changes in FA,A,and Ngroups(P＞0.05); compared with control group, liver indexs of the model groupswere significantly higher(P＜0.05). It was highest in FA group, then F and Agroup, but there wasn't significantly change in both A and F group(P＞0.05)2. hepatic histologic findings:The model groups had remarkable fatty liver, steatohepatitis. The level of steatosisand steatohepatitis were significantly higher than control group (P＜0.05). Amongthe model groups, F and FA group were equal in steatosis (P＞0.05). FA groupwas higher than F and A group at the level of inflammation. 3. Serum biochemistry index in each group: compared with control group, ALT, ASTin experiment groups were increased markably(P＜0.05), thats in FA group werehigher than F and A group, but it was no significantly different between group Aand F(P＞0.05).4. Lipidemia and serum free fatty acid(FFA): serum lipid in experiments group ratswere increased variously(p＜0.05). Except F and A group, there was significantlydifferent in eath other groups. There was statistic different in CHO of each grouprats; except FA and F groups, there was statistic difference in TG of each othergroups; according to FFA, there were no significantly different between group Aand N, group F and FA(＞0.05).5. Measuration of antioxygen indexs in liver tissue: GSH and SOD in experimentgroups decreased variously(P＜0.05). Among the model groups, the mean of GSHand SOD in liver tissue were remarkably higher in FA group than F and Agroup(P＜0.05), and the difference was no significant between F and Agroup(P＞0.05), MDA in experiment group increased remarkably(P＜0.05). FAgroup was highest than other two groups, but there was no significantly differentamong other groups (P＞0.05).6. Measuration of hepatocyte apoptosis indexes in liver speciments:The AI was increased significantly in experiment groups; the AIs in alcoholgroup(2.16±0.43), fat-rich diet group(2.33±0.60), alcohol and fat-rich dietgroup(3.93±0.80) were higher than that in control group(1.07±0.27)(P＜0.05). The apoptosis cells could been found easily in thecentrolobular(zone 3) area in which the inflammation was remarkable. Theapoptosis index was correlated with the degree of inflammation, the level of thecontent of MDA of liver homogenate positively(P＜0.05), and with the GSH,SODof liver homogenate negtively(P＜0.05).7. Expression of caspase-3 protein and mRNA in the liver tissue:The expression of caspase-3 protein and mRNA was significantly increased in theliver tissue of experiment rats, and the highest expression was found in alcohol andfat-rich group, compared with control group, alcohol group, fat-rich diet group (P＜0.01). There was no difference in expression of caspase-3 in fat-rich diet groupand alcohol one (P＞0.05). Apart from it, there was remarkable difference incaspase-3 of other groups(P＜0.05). Factorial analysis indicated that alcohol hadpositive effect on expression of caspase-3 mRNA(P=0.00), high fat diets hadpositive effect on expression of caspase-3 mRNA(P=0.00), both high fat diets andalcohol had significant interaction(P＜0.05).8. Apoptosis body and cells were founded in ultrastructural pathology in liver tissueof model rats.9. correlation analysis of caspase-3, MDA, steatosis and inflammation in experimentgroups:In model groups, the expression of caspase-3 and AI had remarkable positivecorrelation(r=0.829, P＜0.01), however, had a negative correlation with GSH andSOD (r=-0.768, P＜0.01; r=-0.948, P＜0.01 respectively), caspase-3 had positivecorrelation with steatosis and steatosis (r=0.73, 0.85, P＜0.05 respectively,P＜0.01).Result:1. The two pathogenis of alcohol and fat-rich diet together can aggravate liverdamage than one.2. Alcohol and fat-rich diet can induce hepatocyte inflammation, apoptosis,necrosisand fibrosis by increasing oxidative stress and lipid peroxide; the more servereinflammation and oxidative stress, the higher about the rate of hepatic apoptosis.
|
PDF Full Text Request