FIG. 2.

Leptin improves glucose tolerance in STZ-diabetic mice in a dose-dependent manner. OGTTs were performed in nondiabetic controls and STZ-induced diabetic mice receiving different doses of leptin (STZ and 1, 3, 5, or 10 µg/day) or vehicle only (STZ-vehicle) after a 6-h fast on day 19 after surgery. Mice were gavaged with 2 g/kg glucose at time 0. Time course of blood glucose tracking (A) and AUC from 0–90 min (B). Four of five mice treated with 1 µg/day and all STZ-vehicle–treated mice had blood glucose above the detection limit (33.3 mmol/L) at one or more time points in which case values of 33.3 mmol/L were assigned. These groups were not included in statistical analyses. Two mice treated with STZ and 5 µg/day (STZ-5 µg/day) and one mouse treated with STZ and 3 µg/day (STZ-3 µg/day) had blood glucose <2.9 mmol/L at 90 min and were rescued with exogenous glucose. Data from these mice are omitted from the 120-min time point; n = 5 for 0–90 min and n = 3–5 for 120 min. Data are presented as mean ± SEM. NS, not significant.