In vitro culture--a method of pancreatic islet preservation for transplantation.

Pancreatic islets from adult rats, accumulated daily for a period of 2 wk, were cultured in artificial capillary culture units that were perfused with nutrient medium. Viability and functional capacity of these islets in this in vitro culture system has been shown to be maintained. The therapeutic efficiency of cultured islets was comparable to freshly isolated islets when assessed by transplantation into streptozotocin-induced diabetic rats. Intraportal implantation of either freshly isolated or cultured islets into isogeneic diabetic rats resulted in normal weight gain as well as complete reversal of hyperglycemia, glycosuria, and polyuria in the diabetic rat recipient. The normoglycemic state was sustained for more than 12 mo. Plasma glucose clearance rate (KG) were significantly lower in both the transplanted fresh or cultured islet groups than in the normal controls; however, the cultured islets were not less effective than the fresh islets. The results of the present study indicate the feasibility of accumulation of large numbers of islets in the in vitro culture system without any loss of therapeutic efficiency when implanted in vivo. Further improvement of this in vitro culture system can thus be applied in islet preservation for islet transplantation.