FIGURE 6.
ATGL−/− mice are insulino-sensitive and glucose-normotolerant and have a defect in glucose- and arginine-stimulated insulin secretion in vivo. A hyperglycemic clamp was performed in overnight fasted male wild type (ATGL+/+) and ATGL KO (ATGL−/−) mice. A, glucose levels during the clamp. B, insulin levels during the clamp and C, in response to an arginine (Arg) bolus (1 mmol/kg). D, first phase insulin secretion in response to elevated glucose (Gluc) expressed as AUC from 0 to 15 min. E, second phase insulin secretion (AUC) from 15–45 min. F, M/I index of insulin sensitivity calculated by dividing the glucose infusion rate (M) during the last 30 min of the clamp by circulating insulin levels (I) during the same period. M/I index is expressed as μmol·kg−1·min−1 glucose infusion per pmol/liter insulin. G and H, glycemia (G) and insulinemia (H) during an IPGTT in overnight fasted male ATGL+/+ and ATGL−/− mice. Mean ± S.E. are of 9 and 5 animals per group for HGC and IPGTT, respectively. *, p < 0.05; **, p < 0.01; ***, p < 0.001 versus ATGL+/+ for the same time; two-way ANOVA, Bonferroni post hoc test for A–C and G and H, and unpaired two-tailed Student's t test for D–F.