Prolongation of islet xenograft survival (rat to mouse) by in vitro culture at 37 C.

Meticulously selected rat islets were maintained in vitro for 7 days in a minimal volume of tissue culture medium at 37 C in air and 5% CO2. The cultured islets were transplanted into diabetic mice, either into the liver via the portal vein, or beneath the renal capsule. The survival of the cultured islets, following intrahepatic or renal subcapsular transplantation, was significantly prolonged compared with that of fresh islets. The renal subcapsular site apparently provides some additional immunologic advantage, because the survival time of the cultured islets in this site was approximately twice as long as in the intrahepatic transplants.