Insulin inhibits glucagon-induced glycogenolysis normally in perivenous hepatocytes of Wistar fatty rats

Abstract Wistar fatty (WF) rats are obese, hyperinsulinemic and hyperglycemic, and thus a model of type 2 diabetes mellitus. Since we have found that insulin specifically inhibits glucagon-induced glycogenolysis in perivenous hepatocytes (PVH) from normal rats, we examined the inhibitory effect of insulin on glucagon-induced glycogenolysis in PVH of hyperinsulinemic WF rats. Basal glucose release was 64.0±4.1nmol/mgprotein/30min from PVH of lean littermates (WL rats) and 137.0±19.3nmol/mgprotein/30min from that of WF rats ( p p When 10nmol/l insulin was coincubated, 0.1nmol/l glucagon-induced increase in glucose release decreased to 93.3±10.9nmol/mgprotein/30min in PVH of WL rats ( p p Thus, the antagonizing effect of insulin on glucagon-induced increase in glycogenolysis was preserved in PVH of hyperinsulinemic and hyperglycemic WF rats.