Relationship Between Ultrasonic Young's Modulus And Fatty Pancreas In Offspring Rats Induced By Intrauterine Hyperglycemia And High Fat Diet In The Offspring Early Stage

Objective:To study whether the fatty pancreas of offspring rats was associated with intrauterine hyperglycemia and high fat diet in the early stage.To investigate the relationship between ultrasonic Young's modulus(YM)and pathological severity of fatty pancreas.Methods:Twenty pregnant Wistar rats were assigned randomly to two groups:gestational diabetes mellitus group(GDM)and normal blood glucose group(NBG).The rats in GDM group received the intraperitoneal injection of 1% streptozotocin solution.The rats in NBG group received the intraperitoneal injection of equal dose of citrate buffer.The fasting blood glucose were measured on the 3rd,7th,and 12 th days after streptozotocin injection.Rats with hyperglycemia in the range of 13.9–22.2 mmol/L were considered as GDM model rats.Three weeks after offsprings' birth,the offsprings were separated randomly in to high fat diet(HFD)and normal diet(ND).Thus 4 groups were got as follow :GDM+HFD,GDM+ND,NBG+HFD,NBG+ND.Every group had 6 offsprings.GDM+ND group and NBG+ND group fed normal diet.GDM+HFD group and NBG+HFD group fed high fat diet.The offsprings weighed once a week.At third months,every offspring performed oral glucose tolerance test and recorded results.Then,the fasting blood glucose,the total cholesterol(TC),triglyceride(TG)levels in 5ml serum were measured by the automatic biochemical analyzer.The pancreatic microstructure in offsprings was observed under light microscope.The expressions of sterol-regulatory element binding protein-1(SREBP-1)in offsprings' pancreas were determined by Western blot.The YM in offsprings' pancreas was measured by ultrasound shear wave elastography.Results:1.After intervention of dietary,the body mass of rats in GDM+HFD group and NBG+HFD group was lower than rats in GDM+ND group and NBG+ND group(P< 0.05).2.Oral glucose tolerance test: Compared with the rats in NBG + ND group,the rats in GDM + HFD group,the GDM + ND group and the NBG + HFD group showed abnormal sugar tolerance(P< 0.05).3.Biochemical indicators: Compared with the rats in NBG + ND group,the serum fasting blood sugar,triglyceride and total cholesterol levels of rats in GDM + HFD group increased(P< 0.05).Compared with the rats in NBG + ND group,the serum fasting blood sugar and triglyceride levels of rats in GDM + ND group increased(P< 0.05).Compared with the rats in NBG + ND group,the serum triglyceride and total cholesterol levels of rats in NBG + HFD group increased(P< 0.05).4.Pathological changes: The pancreas of rats in NBG + ND group were normal.The pancreas of rats in NBG+HFD group showed fatty change in pancreatic islet cells and acinar cells,fat and inflammatory cell infiltration in interstitial cells.Moreover,the overall degree of lesion in NBG+HFD group is less severe.The pancreas of rats in GDM+ND group showed fatty change in pancreatic islet cells,fat infiltration in interstitial cells.The pancreas of rats in GDM+HFD group showed fatty change in pancreatic islet cells and acinar cells,fat and inflammatory cell infiltration in interstitial cells.Moreover,the overall degree of lesion in GDM+HFD group is the most severe.5.Expressions of SREBP-1 and FAS in the pancreas of offspring: Compared with the rats in NBG + ND group,the expressions of rats in GDM+HFD group,GDM+ND group and NBG+HFD group increased.In addition,the expressions of FAS had a tendency towards the expressions of SREBP-1.There was a positive correlation between the expressions of FAS and the expressions of SREBP-1(r = 0.539,P <0.01).There was no interaction between intrauterine hyperglycemia and high fat diet in the early stage(P >0.05).The main effect of intrauterine hyperglycemia was 0.46(P <0.01).The main effect of high fat diet in the early stage was 0.56(P <0.01).These two factors increased the expressions of SREBP-1.Moreover,the main effect of high fat diet in the early stage was higher.6.Young's modulus in the pancreas of offspring: The more pathological changes were severe,the more YM was low.The YM was negatively correlated with pathological severity of fatty pancreas(r =-0.783,P <0.01).Conclusion:1.Both intrauterine hyperglycemia and high fat diet in the offsprings' early stage could cause glycolipids metabolic disorders.2.The intrauterine hyperglycemia and high fat diet in the early stage could cause fatty pancreas in the offsprings,besides high fat diet in the early stage is more important.There is no interaction between intrauterine hyperglycemia and high fat diet in the early stage.3.The mechanism that intrauterine hyperglycemia and high fat diet in the early stage caused fatty pancreas in the offsprings could be as follow:insulin resistance ?the expressions of SREBP-1 increased ?the expressions of FAS increased ?abnormal lipids deposition in pancreas ?fatty pancreas.4.YM could reflect pathological severity of fatty pancreas.