| Objective:(1) The animal models of minimal hepatic encephalopathy(MHE) were copied.(2) To observe drug's therapeutic effects according to detecting the changes of escape latency of Morris water maze,latency period of brainstem auditory evoked potential,concentrations of blood ammonia,contents of serum endotoxin and observing those of Glu,GluR1,GABA, GABARA in rats' hippocampus of control groups and therapy groups between post-treatment and prior treatment.(3) To explore the mechanism of action of treating MHE by adding glutamine and provide scientific research methed for medication of MHE.Method:65 Wister rats were all measured Morris water maze and brainstem auditory evoked potential(BAEP).Then 10 rats were randomized into normal control group.The other 55 rats began to be made models of hepatocirrhosis with CCl4 composite factors.After 9 weeks,30 rats were confirmed to MHE by measureing Morris water maze and BAEP.We picked out 3 rats of MHE group and 3 rats of normal control group randomly and measured the concentrations of blood ammonia,contents of serum endotoxin of abdominal aorta and cumulative optical density value of Glu,GluR1,GABA,GABARA in cerebrum hippocampus.The other 27 rats of MHE were divided into three groups according to completely randomized design.There were 9 rats every group.They were supplied with normal saline 0.3ml every 100g body weight,lactulose 0.28g every 100g body weight and L-glutamine 0.01g every 100g body weight in the way to intragastric administration once every day,lasting two weeks.The MHE rats were treated with CCl4 factors during using medication.After 2 weeks(namely 11th weeks),we measured all above-mentioned indexs of all rats again.Result:(1) The escape latency of Morris water maze in lactulose and L-glutamine groups in post-treatment were obviously shorter than in prior treatment,and they were significant difference(P＜0.05).The escape latency of Morris water maze in MHE blank group in post-treatment was a little longer than in prior treatment,but they had no obvious difference (P＞0.05).We compared normal control group with therapy groups interblock and found that lactulose group and normal group had no obvious difference(P＞0.05) in post-treatment,but L-glutamine group and MHE blank group were significant difference compared with normal control group(P＜0.05).(2) The latency of the first wave of brainstem auditory evoked potential in lactulose group and L-glutamine group in post-treatment were shorter than in prior treatment, however,MHE blank group in post-treatment were longer than in prior treatment.They were all no significant difference(P＞0.05).They had no obvious difference(P＞0.05) every group between in prior treatment and in post-treatment.The latency of the third wave and the fifth wave of brainstem auditory evoked potential in lactulose group and L-glutamine group in post-treatment were obviously shorter than in prior treatment and they were significant difference(P＜0.05).MHE blank group in post-treatment were longer than in prior treatment and they were no significant difference(P＞0.05).The latency of the third wave and the fifth wave of brainstem auditory evoked potential in L-glutamine group and normal group had no obvious difference(P＞0.05).The latency of the third wave of brainstem auditory evoked potential in lactulose group and normal group were significant difference(P＜0.05) but the latency of the fifth wave of brainstem auditory evoked potential in lactulose group and normal group had no obvious difference(P＞0.05).(3) The concentrations of blood ammonia of abdominal aorta in L-glutamine group and lactulose group in post-treatment were obviously lower than in prior treatment and they were significant difference(P＜0.05).They had no obvious difference compared with normal group(P＞0.05).The concentrations of blood ammonia in MHE blank group were a little more in post-treatment than in prior treatment and they had no obvious difference(P＞0.05),which had significant difference compared with the other three groups (P＜0.05).(4) The contents of serum endotoxin of abdominal aorta in L-glutamine group and lactulose group in post-treatment were obviously lower than in prior treatment,and they were significant difference(P＜0.05).Lactulose group and normal control group had no obvious difference(P＞0.05) while L-glutamine group and normal control group were significant difference(P＜0.05).The contents of serum endotoxin of MHE blank group were a little more in post-treatment than in prior treatment and they had no obvious difference(P＞0.05),which had significant difference compared with the other three groups(P＜0.05).(5) Glu and GluR1 in hippocampus of L-glutamine group and lactulose group increase in post-treatment than prior treatment while GABA and GABARA in hippocampus degrade in post-treatment than prior treatment and the difference were significant(P＜0.05).When we compared the two groups with normal control group,we found Glu had no obvious difference(P＞0.05) and GluR1 had obvious difference(P＜0.05).Glu,GluR1,GABA and GABARA in hippocampus of MHE blank group were no marked changed compared with prior treatment and the difference were no significant (P＞0.05).However,the difference were significant compared with the other three groups (P＜0.05).Conclusion:(1) The escape latency of Morris water maze,latency of brainstem auditory evoked potential can be treated as one of observation index in correlative experimental investigation of MHE.(2) The increase of blood ammonia and serum endotoxin both participate in invasion of MHE and have significant effects on pathogenesy of minimal hepatic encephalopathy,which may be one of judging index of drug therapeutic effect.(3) Glutamic acid in rats' hippocampus of MHE decrease while gamma-aminobutyric acid increase,so it may improve symptoms of MHE that taking orally L-glutamine was absorbed into blood and turned into giutamic acid through blood-brain barrier,(4) GluR1 in rats' hippocampus of MHE decrease while GABARA increase,but we find GluR1 in rats' hippocampus of MHE increase while GABARA decrease by adding L-glutamine,which indicate that adding L-glutamine may have effects on treating MHE. |
