Figure 1.

Upper left panel: oral glucose tolerance test (OGTT) in Zucker rats fasted overnight. Symbols were used to highlight differences between treatment groups for a given time point: £, control group different from Metformin+Melatonin group; @, control group different from Metformin group; &, Metformin group different from Metformin+Melatonin group; $, Metformin group different from Melatonin group. Upper right panel: corresponding area under the curve of OGTT (AUC). Groups with different letters are significantly different (P < 0.05). Lower left panel: ip, insulin sensitivity test (ITT) in Zucker rats fasted overnight. Symbols for statistical differences, as above. Lower right panel: corresponding area under the curve of ITT (AUC). AUC, area under the curve. Met, metformin, MEL, Melatonin