Figure 6.

Impairment of lipolysis because of adipocyte-specific ablation of GPRC6A leads to altered fuel utilization.A, response of control and adG6AKO mice to 24 h of fasting. B, decline in rectal temperature during cold exposure (4 °C). C, serum NEFA levels before and 15 min after intraperitoneal injection of isoproterenol (10 mg/kg) in food-deprived control and adG6AKO mice. D, respiratory exchange ratio (RER) calculated from oxygen consumption (VO₂) and carbon dioxide production (VCO₂) assessed by an indirect calorimetric system over a 24-h period with a 12-h light/dark cycle (day from 8 AM to 8 PM). E, average RER for day and night period. F, cumulative energy expenditure during daytime and nighttime. H, UCP1 expression in brown adipose tissue from control and adG6AKO mice. β-actin was used as a loading control. All quantitative data are the mean ± SEM from at least three independent experiments. ∗p < 0.05, ∗∗p < 0.01 for the indicated comparisons by one-way ANOVA (B) or Student's t test (A, C, and E). NEFA, nonesterified fatty acid; UCP-1, uncoupling protein 1.