Figure 5.
Fasted PPARα-null mice suffer from hypothermia and have a lower metabolic rate than fasted wild-type mice. Only female mice were used for these measurements. (a) Rectal temperature. Measurements were taken at the beginning of the light cycle (fed state) or after a 24-hour fast that was started at the beginning of the light cycle (fasted state). Note that the y axis starts at 20°C. Error bars represent SEM. ANOVA showed a significant difference between fasting and feeding (P < 0.05), genotype (P < 0.01), and interaction between fasting/feeding and genotype (P < 0.01). *Significantly different from fasted wild-type mice (P < 0.01). †Significantly different from fed mice (P < 0.05 [+/+] or P < 0.01 [–/–]). All analyses by post hoc t test. (b) Metabolic rate. For each mouse, mean metabolic rate was calculated for a 23-hour period with free access to food and water (fed state), or during the last 3 hours of a 24-hour fast (fasted state). Error bars represent SEM. ANOVA yielded significant effects for fasting vs. feeding (P < 0.01) and genotype (P < 0.05). *Significantly different from fasted wild-type mice (P < 0.05). †Significantly different from fed mice (P < 0.01). All analyses by post hoc t test.