Figure 3.

Metabolic data from ucp2^+/+ and ucp2^−/− ghrelin-treated mice. Mice were placed in CLAMS metabolic monitoring systems (Columbus Instruments) for 4 d and treated daily with ghrelin (10 nmol, ip, n = 6/group). A, ucp2^−/− mice exhibited a significantly higher RER after ghrelin treatment compared with ucp2^+/+ mice, indicating that the lack of UCP2 reduces fat metabolism. RER is calculated as VCO₂/VO₂. B–E, No significant differences were measured in total VO₂, VCO₂, activity, or heat. All data are expressed as mean ± sem. a, Significant with respect to saline controls; b, significant with respect to ucp2^+/+ ghrelin.