ISLET ISOLATION AND AUTOTRANSPLANTATION IN PIGS

Despite recent considerable progress in the isolation and purification of porcine pancreatic islets the final proof of functional integrity has not yet been performed. In the present study the feasibility, tech nical problems and posttransplant metabolic function of islet transpla ntation in the pig were investigated. Intraductal collagenase perfusio n technique for islet preparation was used in 27 landrace pigs and eig ht minipigs followed by intraportal or intrasplenic transplantation of the islets. Islet purification was performed by dextran gradient in s ix preparations. Islet quantification, portal vein pressure measuremen ts, intra- and postoperative complications and postoperative graft fun ction were monitored. Between 1.73 x 10(5) and 11.4 x 10(5) islet cont aining fragments (8.23 x 10(3) - 54.28 x 10(3) islet containing fragme nts/kg recipient body weight) were transplanted. Portal vein thrombosi s occurred in 4 animals with significantly elevated portal pressure (p =0.0001). 11 of 27 landrace pigs died due to postoperative complicatio ns. None of the minipigs was lost due to perioperative mortality (p=0. 031). Four of eight landrace pigs with intrasplenic grafts (50%) were normoglycemic and two of eight landrace pigs with intrahepatic transpl ants (25%) were normoglycemic. In minipigs two out of four (50%) with intrasplenic transplants and two out of four (50%) with intraportal tr ansplants were normoglycemic. The results in glucose metabolism as mea sured with intravenous glucose tolerance tests and calculated by K-val ues were statistically significantly different between normoglycemic a nd hyperglycemic animals (landrace pigs p=0.0002 and minipigs p=0.0005 ). Longevity was prolonged in normoglycemic animals as compared to hyp erglycemic and apancreatic animals. It ist concluded that successful i slet isolation and transplanation is feasible in the landrace pig and the minipig while the landrace pig appears to be more susceptable to p erioperative mortality.