Role of Endogenous Glucagon-Like Peptide-1 in Islet Regeneration After Partial Pancreatectomy

A reduction in -cell mass is an important causative factor in type 1 and type 2 diabetes. Glucagon-like peptide-1 (GLP-1) and the long-acting agonist exendin 4 (Ex-4) expand -cell mass by stimulating neogenesis and proliferation. In the partial pancreatectomy (Ppx) model, exogenous Ex-4 promotes islet regeneration, leading to sustained improvement in glucose tolerance. In this study, we investigate the potential role of endog-enous GLP-1 in islet growth. We examined -cell mass regeneration after 70 % Ppx in mice receiving the GLP-1 antagonist Ex9-39 and in GLP-1R/ mice. In Ex9-39– treated sham-operated mice, persistent fasting hyper-glycemia was observed, but -cell mass was not diminished. In pancreatectomized mice, persistent glu-cose intolerance was noted, but this was not furthe