Figure 8. Time-of-day-restricted feeding partially restores diurnal metabolic flexibility of cardiac non-oxidative lipid metabolism in obese mice.

Hearts were isolated from mice (at ZT5 and ZT17) that were fed either a control or high fat diet in an ad libitum fashion for 18-wks, followed by food access only during the 12-hr dark (active) phase for 2-wks. (A) Rates of cardiac glucose oxidation (i), fatty acid oxidation (ii), [¹⁴C]-labelled lactate release (iii), net lactate release (iv), net glycogen synthesis (v), and net triglyceride synthesis (vi) in control diet fed mice (n=10–13). (B) Rates of cardiac glucose oxidation (i), fatty acid oxidation (ii), [¹⁴C]-labelled lactate release (iii), net lactate release (iv), net glycogen synthesis (v), and net triglyceride synthesis (vi) in high fat diet fed mice (n=10). (C) Volcano plots indicating day-night differences in the cardiac lipidome of control (i) and high fat fed (ii) mice; color indicates distinct lipid species classification (n=8–9). (D) Relationship between MS signal intensity values for individual annotated triglycerides in (i) control and (ii) high fat fed mice expressed as fold changes between ZT17 and ZT5 (log2) with carbon chain length (i) and degree of unsaturation (ii) of cardiac lipid species (n=8–9).