Dietary macronutrients modulate the fatty acyl composition of rat liver mitochondrial cardiolipins

The interaction of dietary fats and carbohydrates on liver mitochondria were examined in male FBNF1 rats fed 20 different low-fat, isocaloric diets. Animal growth rates and mitochondrial respiratory parameters were essentially unaffected, but mass spectrometry-based, mitochondrial lipidomics profiling revealed increased levels of cardiolipins (CLs), a family of phospholipids essential for mitochondrial structure and function, in rats fed saturated or trans fat-based diets with a high glycemic index. These mitochondria showed elevated monolysocardiolipins (a CL precursor/product of CL degradation), elevated ratio of trans PC (18:1/18:1) to cis PC (18:1/18:1) (a marker of thiyl radical stress), and decreased ubiquinone Q9 -- the latter two of which imply a low-grade mitochondrial redox abnormality. Extended analysis demonstrated: (i) dietary fats and, to a lesser extent, carbohydrates induce changes in the relative abundance of specific CL species; (ii) Fatty acid (FA) incorporation into ...