SITE FOR UNPURIFIED ISLET TRANSPLANTATION IS AN IMPORTANT PARAMETER FOR DETERMINATION OF THE OUTCOME OF GRAFT-SURVIVAL AND FUNCTION

Transplantation of unpurified islets into the liver, unlike that of pu rified islets, causes portal hypertension and coagulopathy. The aim of this project was to determine the most suitable alternative site for transplantation of purified pancreatic islets in autotransplanted dogs . Twenty-five female mongrel dogs were divided into 5 groups depending on the site of islet transplantation: liver (3), spleen (7), skeletal muscle (5), omental pouch (6), and renal subcapsule (4). Pancreatic d igestion of the total pancreatectomized specimen was carried out by di stension of the pancreas with 1.5 mg/mL collagenase suspended in 250 m L Hanks' balanced salt solution using a semiautomatic method. The tota l number of islets equivalent isolated from 25 dogs was 90948 +/- 6053 . Only islets > 60 mu m in diameter were counted, and the mean islet e quivalent transplanted per kg body wt was 6762 +/- 429. Islet function was achieved with transplantation into spleen in 71%, omental pouch i n 50%, and muscle in 20%, but none in the renal subcapsule or liver gr oups. Glucose tolerance test at 30 d showed a mean K Value (decline in glucose, %/min) of 1.94 +/- 0.73, 0.79 +/- 0.15 and 1.02 in the splen ic, omental pouch and muscle groups, respectively. All animals in the liver groups, 2 from the splenic group, and 2 from the renal subcapsul e group died of diffuse bleeding. Four out of 5 dogs in the muscle gro up developed necrosis at the site of transplantation and the islets ne ver functioned. This study demonstrates that in dogs, spleen and oment al pouch appear to be suitable sites for transplantation of unpurified islets.