| Objective:PI3K/Akt signal transduction pathway is the most obvious signal transduction pathway that acts on insulin.For insulin,liver is an important target organ and plays a great role in lipid metabolism and glucose metabolism.Further research on this signaling pathway can add more new ideas to the discussion of the pathogenesis of diabetes.To investigate the effect and mechanism of high intensity intermittent exercise on PI3K/Akt/mTOR signaling pathway in the liver of type 2 diabetic rats during model porcess,and to provide a theoretical basis for the development of exercise program to prevent diabetes and diabetic liver complications.Methods:A total of 18 healthy male SD rats were randomly divided into normal control group,diabetes control group and high intensity intermittent exercise group after a week of normal diet adaptive feeding.They were NC group,DM group and HIIT group respectively,with 6 rats in each group.Each group received two weeks of non slope animal treadmill adaptive exercise training,with the training intensity of 10m/min and 40min per day And the speed increased from 2m/min to 20m/min every day.NC group was fed with normal diet and free activity lasted for 8 weeks.DM group was fed with double high diet and free exercise for 8 weeks.HIIT group,fed with double high diet,took the animal treadmill for high intensity intermittent exercise training,the exercise intensity was:(4 min,42 m/min,10°+5 min,18 m/min,0°)× 4+4 min,7m/min,0° each time,40 min,5 times a week,lasting for 8 weeks.At the end of 8 weeks,the body weight and fasting blood glucose of each group were measured.In NC group,0.1mmol/l citric acid buffer was used for one-time intraperitoneal injection according to the proportion of 30mg/kg;in HIIT group and DM group,2%STZ solution was used for one-time intraperitoneal injection according to the proportion of 30mg/kg.7 days later,the body weight and tail vein blood were measured in the morning,and the random blood glucose of rats in each group was measured to determine the modeling rate.Then the liver was taken out by laparotomy,and part of it was used for HE staining to observe the liver tissue morphology and liver nuclear measurement;part of it was frozen for WB to detect the protein expression of PI3K,Akt,p-Akt(ser473),p-Akt(thr308)and mTOR.Results:1.Morphological structure of liver:the normal control group(NC)rats’ liver had a relatively complete lobular structure,with normal nuclear size,nuclear membrane and nucleolus morphology.The hepatocytes were arranged in a normal cord like structure along the central vein,without fat vacuolar degeneration.Normal hepatic sinuses could be observed,and there was no proliferation of bile ducts in liver portal area In diabetic control group(DM),the structure of hepatic lobule was disordered and the cord like structure disappeared,and the sinusoidal space was enlarged,the boundary of hepatocytes was not clear,the cells appeared in water,the formation of fat vacuoles,the pyknosis of nuclei,and the proliferation of bile ducts in the portal area were observed;compared with diabetic control group(DM),the high-intensity intermittence was observed In group HIIT,the structure of hepatic lobules was intact,with clear cord like arrangement of hepatocytes,no obvious fat vacuolar degeneration and cell edema were found,and a small amount of hyperplasia was formed in the portal area.Nuclear morphology was observed by HE staining under 400x-ray microscope:compared with the number of nuclei around the portal area of normal control group(NC),the number,average diameter,total area and total area of chromatin around the portal area of diabetic control group(DM)were significantly decreased(P<0.01),while the number,average diameter and total area of nuclei around the portal area of high intensity intermittent group(HIIT)were significantly decreased(P<0.01)The diameter,total area and total area of chromatin decreased significantly(P<0.01);compared with diabetic control group(DM),the number and average diameter of nuclei in portal area increased significantly in high intensity intermittent group(HIIT)(P<0.05),and the total area of chromatin increased significantly(P<0.01).2.The relative expression level of PI3K protein in liver tissue of high intensity intermittent group(HIIT)was higher than that of diabetic control group(DM);the relative expression level of Akt protein in liver tissue of diabetic control group(DM)was lower than that of normal control group(NC);the relative expression level of Akt protein in liver tissue of high intensity intermittent group(HIIT)was higher than that of diabetic control group(DM)Compared with the control group(DM),there was an increasing trend.The relative expression level of p-Akt(ser473)protein in liver tissue of diabetic control group(DM)was higher than that of normal control group(NC),and the relative expression level of p-Akt(ser473)protein in liver tissue of high intensity intermittent group(HIIT)was lower than that of diabetic control group(DM).The relative expression level of p-Akt(thr308)protein in liver tissue of diabetic control group(DM)rats was higher than that of normal control group(NC);the relative expression level of p-Akt(thr308)protein in liver tissue of high intensity intermittent group(HIIT)and diabetic control group(DM)rats was similar.The relative expression level of mTOR protein in liver tissue of diabetic control group(DM)was higher than that of normal control group(NC),and the relative expression level of mTOR protein in liver tissue of high intensity intermittent group(HIIT)was lower than that of diabetic control group(DM).There was no significant difference in each group(P>0.05).Conclusions:1.The morphology and structure of liver tissue of type 2 diabetic rats showed obvious fat vacuoles and lipid degeneration,obvious edema of liver cells,disordered and irregular structure of liver tissue,and the number,total area,mean diameter and total area of chromatin in the adjacent vascular region of liver tissue of rats were significantly decreased.Eight weeks of high-strength intermittent motion can be in a certain degree of influence of type 2 diabetes rat liver tissue morphological structure in the process of building,improve the liver cell edema,reduce the formation of rat liver tissue fat vacuoles,effectively maintain the liver portal area near the nucleus number,total area and average diameter and the total area of chromatin,reduce the nucleus pycnosis,maintain the normal form of the nucleus.2.There were no significant differences in the relative expression levels of PI3K,Akt,p-Akt(Ser473),p-Akt(Thr308)and mTOR in the liver of normal control group(NC),diabetes control group(DM)and high intensity intermittent group(HIIT).During the modeling process of type 2 diabetes in rats,8 weeks of high-intensity interval exercise did not significantly affect the activation of PI3K/Ak/-mTOR signaling pathway. |
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