Fig. 3.

Physiological effects of leptin treatment on ob/ob mice. (A) The ob/ob mice received daily i.p. injections of leptin between 3 and 4 mo of age. Body weight and blood glucose and plasma insulin levels were monitored before, during, and after the treatment; the beginning and end of treatment are represented by vertical dashed lines. (B) The i.p. glucose tolerance tests show impaired glucose handling in the ob/ob mice compared with control littermates at the age of 4 mo (Top), which is normalized by leptin treatment but not by sham treatment (Middle). (Bottom) Bar graph showing area under the curve (AUC) values from the above traces, demonstrating the beneficial effect of leptin on glucose handling. Values are average ± SEM. **P < 0.01; ***P < 0.001.