| Objective:To establish a rat model of type 2 diabetes using a high-fat and high-sugar diet combined with intraperitoneal injection of streptozotocin(STZ),and to add exercise interventions during the establishment of the model to explore the occurrence of diabetes during moderate-intensity exercise interventions.The impact of liver damage.Methods:30 SPF grade six-week-old male SD healthy rats were randomly divided into 3 groups with 10 rats in each group after one week of adaptive rearing:Group A(normal control group);Group B(diabetes control)Group);Group C(exercise intervention group).Group A was fed as a control group,and rats in groups B and C were given an intraperitoneal injection of low-dose STZ(30 mg/kg)once a week in a high-sugar and high-fat diet,and group C was administered at the same time with high-fat and high-fat diets.Medium intensity sports treadmill training.Rats in groups A and B were kept in cages and were free to exercise without additional exercise intervention.The animals were sacrificed on the 7th day after STZ injection.The liver tissues were harvested and HE and Masson staining were performed for morphological observation,and the expression of a-SMA in liver tissues of each group was observed by immunohistochemistry.Eyelid blood was collected to measure serum type IV collagen concentration.Results:1.Group B rats showed polydipsia,polyphagia,polyuria,lack of energy,dull hair color,etc.On the 7th day after STZ injection,the tail vein blood was taken and the random blood glucose was measured.The blood glucose was above 16.7mmol/L,suggesting that the diabetic rat model is successful.2.Morphological changes of hepatocytes:1)Observed by HE staining under 200×light microscope:A group of liver tissue,clear hepatic lobules,clear liver plate,round cell nuclei,uniform size,complete nuclear membrane,nucleoli Clear,hepatic cord radially arranged,without vacuolar degeneration,normal hepatic sinusoids,no proliferative bile ducts in the portal area;group B liver,hepatic lobule structure disorder,border is not clear,a large number of fat vacuoles,liver The cells appeared watery degeneration,the cell structure disappeared,the nucleus pyknosis,hepatic sinusoids dilated,hepatic congestion,bile canal hyperplasia occurred in the portal area,and fibroblast proliferation was observed;the liver tissue and hepatic lobule structure in the group C was still clear.The cord-like structure of the cells is still clear,with visible hepatic plate,no obvious fat vacuoles,slight swelling of hepatocytes;hepatic sinusoidal stenosis,and slight hyperplasia of bile ducts in the portal area.2)Masson staining under 200× light microscope showed that:in group A,the structure of hepatic lobule was normal,and no blue-stained fibers were evident;fat vacuoles appeared in liver tissue in group B;hepatic lobule structure was severely damaged;and blue-stained collagen was evident in the portal area.Mild blue-stained collagen fibers were observed between fibers and hepatocytes.The structure of hepatic lobule was relatively normal in group C,no obvious fat vacuoles were observed,hepatic edema increased,and no blue staining of collagen fibers was observed in the hepatocyte space.3.The expression of a-SMA in the liver tissues of rats in each group was observed by immunohistochemistry.The immunohistochemical staining of a-SMA in group A was observed in the small arteries and venules,and expressed in the bile duct.Less;the immunohistochemical staining of a-SMA in liver tissue of group B was mainly expressed in the portal area and fibrosis;the positive immunohistochemical staining of a-SMA in liver tissue of group C was less expressed in the portal area.The cumulative optical density(IOD)results of the image analysis software showed that the expression levels of a-SMA in group B and group C were significantly higher than those in group A(p<0.05),while the expression of a-SMA in group C was higher than that in group B.There was a significant reduction(p<0.05).4.The liver of the diabetic control group had early fibrosis and its type IV collagen increased.The concentration of type IV collagen in group A was 3.45±2.26 ng/ml,and the concentration of type IV collagen in group B was 7.53±2.02 ng/ml,P<0.05 was considered statistically significant.However,the concentration of type IV collagen in group C was 4.27±3.46 ng/ml,which was significantly lower than that in group B.P<0.05 was considered statistically significant.It was shown that exercise intervention can reduce early hepatic fibrosis in the process of diabetes.Conclusion:1.Middle-intensity exercise can protect liver tissue morphological structure of diabetic rats induced by high fat and high sugar diet combined with STZ,reduce the formation of fat vacuoles in liver tissue of rats,and effectively improve hepatocyte water degeneration and hepatic sinusoidal dilation.2.Moderate-intensity exercise intervention can reduce the expression of a-SMA in the liver tissue of the diabetic rats induced by high-sugar and high-fat diet combined with STZ-induced diabetic rats,and reduce the activation of hepatic stellate cells,thereby reducing liver fibrosis.3.Moderate intensity exercise intervention can reduce the hyperplasia of hepatic tissue and hepatic interstitial collagen fibers in high fat and high glucose diet combined with STZ-induced diabetic rats.At the same time,it can reduce the concentration of serum type Ⅳcollagen and reduce hepatic fibrosis. |
PDF Full Text Request