[Results of islet transplantation in diabetic dogs]. / Ergebnisse der Inseltransplantation bei diabetischen Hunden.

The influence of histocompatibility on islet transplantation in dogs was studied. Donors and hosts were chosen by help of the macrophage-electrophoresis-mobility test. By subtotal pancreatectomy and twice applying streptocotocin diabetes was successfully induced in recipient animals. Isolation of pancreating islets from the donor was done by means of the collagenase method combined with the Ficoll-gradient-separating technique. The grafting occurred via portal vein into the liver. Significant decrease of blood sugar during 10 weeks was observed in animals with good compatibility. This effect lasted only 14 days in cases of bad compatibility. Concentrations of insulin in the portal vein and superior caval vein 4 weeks after grafting was lower in cases with high-grade histoincompatibility. The duration of functioning of transplanted islets depends on the histocompatibility.

Transplantation of isologous islets of Langerhans in diabetic rats. Long-term immunohistochemical results.

Isologous isolated islets of Langerhans were transplanted into the peritoneum and through the portal vein into the liver of diabetic rats. This resulted in the normalization of fasting blood glucose levels, with clear improvement of glucose tolerance tests. The results after intrahepatic implantation were better than after intraperitoneal implantation. Three months after implantation of islets into the peritoneum diabetes recurred and after one year only 2 of the 15 rats were alive, with high blood glucoe levels. In the group with intrahepatic islets the normalization of blood glucose was maintained over a period of one year. Immunohistochemical insulin proofs were positive in the peritoneum over a period of 3 months and in the liver up to one year after implantation. Glucagon proofs were positive in the intraperitoneal islets for 6 weeks and in intrahepatic ones for one year. Morphological examination of transplanted islets suggested that the liver is better suited for islet transplantation than the peritoneum.

[Transplantation of isolated islets of Langerhans into the liver of diabetic dogs (author's transl)]. / Transplantation isolierter Langerhans'scher Inseln in die Leber diabetischer Hunde

Isolated islets of Langerhans were transplanted through the portal vein in the liver of 8 diabetic dogs; In 4 dogs a homologous transplantation was performed and another group of four dogs received isolated islets from their sisters or brothers. In both groups, there was an immediate effect on the blood glucose level. After pancreatectomy and injection of Alloxan the blood glucose rose to between 350 and 420 mg per 100 ml and after islet implantation the blood glucose decreased between 80 to 160 mg per 100 ml. The iv GTT'S were after islet implantation clear better than in the diabetic control animals. These results could maintained in the recipients with homologues islets over a period of 6 to 8 weeks and in the other group of dogs over a period of 6 to 12 months. We were able to show, that the islet implantation in the liver of diabetic dogs did not disturb the microscopic architecture of the liver. No signs of portal hypertension, hepatic congestion and embolism were found.