Diet effects on membrane phospholipid fatty acids and mitochondrial function in BHE rats

Area of Science:

• Biochemistry
• Nutrition Science
• Mitochondrial Biology

Background:

• Dietary fats significantly impact cellular composition and metabolic function.
• Hepatic mitochondrial function is crucial for energy homeostasis and is sensitive to dietary modifications.
• Understanding the effects of different fatty acids on liver mitochondria is key to metabolic health.

Purpose of the Study:

• To investigate the impact of dietary corn oil versus coconut oil on hepatic phospholipid fatty acid composition.
• To assess the effects of these diets on key hepatic mitochondrial functions, including respiration and shuttle activities.
• To determine if saturated fats from coconut oil influence mitochondrial coupling efficiency.

Main Methods:

• Male BHE weanling rats were fed diets containing 5% corn oil or 5% coconut oil.
• Hepatic tissue was analyzed for phospholipid fatty acid composition.
• Mitochondria were isolated to determine ATPase activity, shuttle activities (alpha-glycerophosphate, malate-aspartate), and respiratory states (supported by succinate or pyruvate).

Main Results:

• Coconut oil diet increased saturated fatty acids in liver phospholipids compared to corn oil.
• Alpha-glycerophosphate shuttle activity was higher in rats fed coconut oil.
• Coconut oil diet led to increased state 4 respiration with succinate and evidence of uncoupling of pyruvate-supported respiration.

Conclusions:

• Dietary coconut oil alters hepatic phospholipid fatty acid profiles.
• Coconut oil consumption enhances the activity of the alpha-glycerophosphate shuttle and affects mitochondrial respiration.
• Saturated fats, like those in coconut oil, may potentiate inherent tendencies for looser coupling of mitochondrial respiration to ATP synthesis in BHE rats.