HYPERTRIGLYCERIDEMIC MICE TRANSGENIC FOR THE HUMAN APOLIPOPROTEIN C-III GENE ARE NEITHER INSULIN-RESISTANT NOR HYPERINSULINEMIC

Plasma glucose and insulin concentrations and in vivo and in vitro est imates of insulin action were compared in hypertriglyceridemic apolipo protein C-III transgenic mice (mean +/- SE triglyceride concentration = 11.8 +/- 0.9 mmol/l) and their normotriglyceridemic (1.1 +/- 0.1 mmo l/l) littermates. There were no differences in the glucose (8.9 +/- 0. 2 vs. 9.3 +/- 0.5 mmol/l) or insulin (172 +/- 21 vs. 203 +/- 17 pmol/l ) concentrations of the transgenic and control mice, respectively. Ste ady state plasma glucose concentrations at the end of a 150-min period of physiological hyperinsulinemia were also in transgenic (6.2 +/- 0. 5 mmol/l) and control mice (6.7 +/- 0.5 mmol/l). As the steady-slate p lasma insulin levels were essentially identical in the two groups (sim ilar to 1000 pmol/l), these results show that whole body insulin-media ted glucose disposal was unchanged in the transgenic mice. Finally, va lues for isoproterenol-stimulated lipolysis, insulin-inhibition of lip olysis, and insulin-stimulated glucose disposal were similar in adipoc ytes isolated from transgenic and control mice. It can be concluded fr om these data that insulin resistance does not develop in hypertriglyc eridemic mice transgenic for the human apolipoprotein C-III gene.