Islet graft-induced changes of ß-hydroxybutyrate dehydrogenase and glucose-6-phosphatase activity in liver cells of diabetic recipient rats

Summary It is known that the liver is a favourable site for implantation of pancreatic islets since the grafted islets remain metabolically intact and provide long-term normoglycemia in diabetic animals.However, the long-term effects exerted by the grafted tissue on the host organ are not well defined.We therefore investigated by light and electron microscopy the effects of syngeneic islets on the host organ after intraportal transplantation into the liver of streptozotocin (STZ)-induced diabetic LEW.1W rats.In addition, tissue sections of graft-bearing liver were stained by enzyme histochemical methods for s-hydroxybutyrate dehydrogenase (HBDH) and glucose-6-phosphatase (G6Pase).At 12 weeks after transplantation, the changes seen in the hepatocytes surrounding the grafted islets were hyperproliferation and accumulation of glycogen.Hepatocytes adjacent to the implanted islets displayed increased HBDH activity, whereas G6Pase activity was variable, either decreased or increased.Increased HBDH activity was also observed in the periportal region and in liver cells extending to the central veins.The results demonstrate that intraportal islet grafts, in addition to normalizing glucose homeostasis, exert remarkable effects on the liver parenchyma of experimentally diabetic recipient rats.