Figure 5.

The difference in response to adrenergic stimulation in C57BL/6 and Aston ob/ob.

Values are taken from (19). (A) Body weight of ob/ob is higher in both strains, with the Aston mice generally being larger, similarly to most other outbred strains. (B) Metabolism per whole mouse in pentobarbital-anesthetized lean and ob/ob mice of the C57BL/6 and the Aston strain are shown before and after injection of norepinephrine. Basal metabolism is higher in ob/ob mice of each strain, compared with lean controls. Aston mice display higher basal metabolism than C57BL/6 mice, most likely a reflection of their higher body weight (A). Norepinephrine causes responses in all groups, with Aston mice displaying a higher response. B, basal metabolism; NE, norepinephrine-induced metabolism. (C) Quantification of the norepinephrine-induced increase over baseline shows reduced responses in ob/ob mice of the Aston strain as compared with their lean controls, but no difference between lean and ob/ob on the C57BL/6 background.