Pancreatic glycogen content in Goto-Kakizaki rats.

In situations of sustained hyperglycemia, much larger amounts of glycogen accumulate in islet B-cells than in other pancreatic cells. The labelling of such a glycogen pool could thus conceivably provide a mean for assessing the relative contribution of insulin-producing cells to the total pancreatic mass. In such a perspective, the present study aims at investigating pancreatic glycogen accumulation in hereditarily diabetic Goto-Kakizaki (GK) rats. When cultured at 30 mM D-glucose in the presence of D-[U-14C]glucose, pancreatic islets from GK rats accumulated 14C-labelled glycogen in a manner comparable to that previously documented in islets from normal rats. Likewise, the glycogen content of the pancreatic gland, relative to the plasma D-glucose concentration, was not different in GK and normal rats. The GK rats thus apparently represent a suitable model for further studies on the in vivo labelling of B-cell glycogen in the perspective of the non-invasive imaging and quantification of the endocrine pancreas.