Improving Islet Yield And Function By Pancreatic Ductal Preservation

Islet transplantation, which can achieve euglycemia without severe hypoglyce-mia episode of intensive insulin therapy and reduce complications, has proved to be a promising and highly effective treatment for type 1 diabetes mellitus. Besides, the technique of islet transplantation is simple, safe and less trauma. Islet yield and func-tion is important to islet transplantation. This study investigates whether pancreatic ductal preservation (pancreatic ductal injection of sparing TIUW solution at the time of pancreas procurement) would improve islet yield and function and observes the therapeutic effect of islet transplantation for diabetes mellitus, then evaluates the pro-tective effect of pancreatic ductal preservation by detecting the percentage of viable pancreatic duct cells and distribution of collagenase in pancreas.Objective (1) To investigate whether pancreatic ductal preservation would improve islet yield and function from rat pancreases cold preserved for 6h and 24h. (2) To evaluate the protective effect of pancreatic ductal preservation.Methods Pancreases from SD rats were classified into five groups: fresh pancreases (group1,n=10); preserved for 6 hr in TIUW solution without and with pancreatic duc-tal preservation by TIUW solution (group2,n=10 and group3,n=10); preserved for 24 hr in TIUW solution without and with pancreatic ductal preservation by TIUW solu-tion (group4,n=10 and group5,n=10). (1) Dithizon (DTZ) staining was used to iden-tify islet morphous and yield, trypan blue uptake (TBU) was used to assess the non-viability of islets and pancreatic ducts, glucose stimulated insulin secretion of islet was used to evaluate its function in vitro. (2) Islet transplantation was used to deter- mine islet function in vivo. (3) HE staining and TBU were used to detect the percent-age of viable pancreatic duct cells, the ink staining and paraffin section were used to observe the distribution of collagenase in pancreas.Results (1) Islet yields per pancreas after purification in group 1 to 5 were 590±127, 272±50, 454±65, 253±56, 447±66 (IEQ±SD), respectively. Percentage of nonviable of islets in group 1 to 5 were (5.7±4.2)%, (18.3±6.5)%, (11.7±4.2)%, (26.3±5.6)%, (15.0±5.3)%. Stimulation index in group 1 to 5 were 7.32±2.32, 4.81±1.17, 7.56±2.44, 2.88±1.00, 5.71±1.90. (2) Cure rates of diabetes mellitus in group 1 to 5 were100%, 0%, 100%, 0%, 70%. (3) Percentage of nonviable pancreatic duct cells in group 1 to 5 were (5.5±3.0)%, (58.6±9.1)%, (16.8±4.9)%, (64.4±8.1)%, (17.2±3.0)%, and there was no significant difference between group 3 and group 5 (P>0.05); The collagenase distributed more evenly in groups 3 and 5 than in groups 2 and 4. In this study, the differences were significant between control groups and experimental groups (P<0.05, group 2 vs. group3 and group4 vs. group5).Conclutions (1) The pancreatic ductal preservation improves islet yield and function from rat pancreases cold preserved for 6h and 24h. (2) Pancreatic ductal preservation can save the integrity of the pancreatic duct system which has been the basic of even distribution of collagenase. The viability of the pancreatic duct cells do not weaken with time.