医科大学精品课件：HE.ppt

1、Animal Experiment Hepatic Encephalopathy Hepatic encephalopathy is a neuropsychiatric syndrome occurred secondarily to severe hepatic disease. It is characterized by mental confusion, muscle tremors and asterixis. BACKGROUND 1. To create an animal model of hepatic encephalopathy, observe manifestati

2、ons of the experimental animal. 2. To understand the role of ammonia in the development of hepatic encephalopathy. PURPOSE The animal model of HE is established by ligating partial liver lobes and perfusing compound NH4Cl from the duodenum of rabbit. The rabbit will appear the signs and symptoms sim

3、ilar to those of HE. PURPOSE Rabbits weighing 2-3kg are used. ANIMAL 1. 20% urethane 2. 2% NH4Cl (ammonium chloride) 3. Rabbit-fixing table 4. 2ml and 5ml Syringes INSTRUMENTS AND CHEMICALS 5. Operating scissors 6. Operating knife 7. Hemostatic forceps 8. Smooth forceps 9. Ophthalmic scissors INSTRU

4、MENTS AND CHEMICALS 1. Weigh the rabbit on a platform balance. 2. Induce general anesthesia with a slow injection of 4ml/kg body weight of 20 urethane solution through a marginal ear vein. STEPS 3. Bind the rabbit on the rabbit-fixing table (dorsal position). 4. Cut off the hair on the abdomen. 5. I

5、nduce local anesthesia with injection of procaine on the middle line of the epigastrium. 6. Make an incision on the middle line of the upper abdomen (about 6-8cm, under xiphoid process 2cm). STEPS STEPS The rabbits are divided into two groups: The experimental group The control group the roots of th

6、e liver lobes are ligated the roots of the liver lobes are not ligated STEPS 8. Ligate partial liver lobes in the experimental group. Blunt dissect the falciform ligament. Turn the liver up to the side of the head. Blunt dissect the hepatogastric ligament to free the liver lobes. Only experimental g

7、roup STEPS 8. Ligate partial liver lobes in the experimental group. Put a cotton thread under the liver. The roots of partial liver lobes are tied with the cotton thread to stop blood flow to liver. Only experimental group While in the control group, the roots are not tied. STEPS 8. Insert a rubber

8、tube into the duodenum for infusion of NH4Cl Find duodenum along the gastric pylorus. STEPS 8. Insert a rubber tube into the duodenum for infusion of NH4Cl Find duodenum along the gastric pylorus. Put two threads under the duodenum, ligate with a thread near the stomach to block gastric contents. Ma

9、ke an inclined cut towards the intestine with ophthalmic scissors. Insert a rubber tube into the duodenum towards the intestine, and fix it with the other thread. Place the liver and duodenum back into the abdominal cavity and use hemostats to close the cavity. STEPS 9. Record respiratory rate under

10、 normal conditions. 10.Infuse compound NH4Cl solution into the duodenum from the cannula, 10ml every 3min. 11.Record respiratory rate and other changes every 3min. 12.After observing the appearance of intense tremor and spasm, which resemble the symptoms of HE, stop infusing compound NH4Cl. 13.Recor

11、d the total dosage of compound NH4Cl solution and the consuming time. 14.Observe and compare the results between experimental and control groups. DISCUSSION Explain how to increase the blood ammonia in this experiment? Based on the experimental results, explain ammonia role in pathogenesis of hepatic encephalopathy and liver function of detoxification.