PANCREATIC BETA-CELL REPLICATION AND AMELIORATION OF SURGICAL DIABETES BY REG PROTEIN

We previously isolated from a rat regenerating islet cDNA library a ge ne named Reg, which is expressed in regenerating islets but is not exp ressed in normal islets. Here we examined the effect of rat Reg protei n on pancreatic beta-cell replication using both 90% depancreatized ra ts and isolated islets. The depancreatized rats that received i.p. adm inistration of recombinant rat Reg protein (1 mg/kg per day) for 2 mon ths showed amelioration of the surgical diabetes, as evidenced by a si gnificant decrease in blood glucose with an increased beta cell mass i n the residual pancreas, In isolated rat islets, Reg protein (18-180 n M: 0.3-3 mu g/ml) significantly increased [H-3]thymidine incorporation into the nuclei of beta cells. These results indicate that Reg protei n is a growth factor for pancreatic beta cells and also suggest that t he administration of Reg protein could be used as another therapeutic approach for diabetes mellitus.