Comparison of Two Methods of Islet Preparation and Transplantation in Dogs

Abstract

Seventy-nine mongrel dogs underwent total pancreatectomy. Fifteen dogs served as apancreatic controls and died 7.0 +/- 4.2 days later (mean +/- SD). The pancreases of 44 dogs (group 1) were intraductally distended by manual injection of Hanks' balanced salt solution (HBSS). Thereafter each organ was mechanically disrupted and subjected to collagenase digestion as described by Mirkovitch et al. The pancreases of 20 dogs (group 2) were intraductally distended and subsequently perfused with collagenase by a roller pump. The organs were then mechanically disrupted and filtered through screens as described by Horaguchi et al. The resulting tissue suspensions were injected into the spleens of the dogs as autotransplants in both groups, by direct punction of the splenic capsule in group 1 and by retrograde infusion via a splenic vein tributary in group 2. The functional outcome was better in group 2 than in group 1, as assessed by the number of animals that became normoglycemic after transplantation [15/20 (75%) vs. 13/44 (30%); P = .0025]. The degree of islet purification, as measured by an increase in the tissue insulin/amylase ratio, was higher in group 2, and in both groups it was higher in normoglycemic than in hyperglycemic animals. The percent engraftment [i.e., amount of insulin recovered from spleen as percent of tissue transplanted (mean, 15.4% in group 1 and 14.5% in group 2) or as percent of original pancreas (mean, 4.9% in group 1 and 4.4% in group 2)] was low in both groups but again was higher in normoglycemic than in hyperglycemic animals within each group. In conclusion, both the degree of engraftment and purification and the route of implantation influenced the functional outcome after dispersed pancreatic islet autotransplantation to the spleen of totally pancreatectomized dogs, with purified tissue injected retrogradely functioning better than unpurified tissue injected directly.

Canine Pancreatic Islet Transplantation: A Comparison of Two Isolation Techniques

“…Unlike Horaguchi and Merrell [7] we were unable to perform successful intrahepatic islet transplants following type A isola tion. The results of intrasplenic transplanta tion of type A islets obtained in the present study, with reversal of diabetes in 5/6 dogs (83%), are similar to those described at the original presentation of this technique [7], In a previous study conducted in our laboratory type A isolation resulted in successful in trasplenic grafts in 15/20 dogs (75%) [11]. Type B islets could in the present study be transplanted in the spleen as well as in the liver with a comparable outcome; 5/8 (63%) and 6/8 (75%) dogs became normoglycemic, respectively.…”

“…The insulin content of the final tissue preparation as well as the total pancreatic insulin content (calcu lated from the sum of the insulin of the final tissue preparation and the insulin content of all washes and discarded tissue) are measured by the double-antibody radioimmunoassay technique of Morgan and Lazarow [10], as described earlier [11]. Tissue amy lase content is similarly measured by the colorimetric technique of Jamieson et al [12], The islet yield is calculated as the percentage of the total pancreatic insulin content found in the final tissue preparation.…”

How to Use Image Analysis for Islet Counting

“…Insulin and zinc content are investigated and compared to islet volume. Hesse et al proposed an ingenious method of estimating islet mass by using insulin/amylase ratios [2]. According to this method, insulin represents endocrine tissue, amylase content defines the degree of exocrine contamination.…”

Human Islet Autotransplantation to Prevent Diabetes after Pancreas Resection

“…In comparison, the latter method is the most commonly preferred [90, 105]. Early reports of human splenic islet allotransplantation advocate direct parenchymal injection [107], although the results were disappointing.…”

“…A number of different techniques of splenic islet autotransplantation have been described including direct intrasplenic injection [11, 101, 102], arterial [11]and retrograde venous infusion [40, 103, 104, 105, 106]. In comparison, the latter method is the most commonly preferred [90, 105].…”