Influence of different dietary concentrations of linoleic acid on the essential fatty acid (EFA) status and functional characteristics of porcine hepatic and cardiac mitochondria

The effect of different dietary concentrations of linoleic acid (0.2, 1.1 and 2.1% of gross energy in experiment 1 and 0.7, 1.6 and 2.3% of gross energy in experiment 2) on the EFA status and the functional characteristics of hepatic and cardiac mitochondria was investigated in pigs raised for 140 days from 10 to 105 kg live wt on their respective diets. As judged from the ratios of 20:3n9 to 20:4n6 of hepatic and cardiac mitochondrial total lipids the pigs receiving 0.2% of dietary gross energy as linoleic acid were EFA-deficient, while the pigs receiving 0.7% of dietary gross energy as linoleic acid were on the borderline of EFA deficiency. Mitochondrial protein yield and the functional parameters (endogenous respiration, respiration of exogenous NADH, state 2, 3 and 4 respiration, RCI-values, ADP/O ratios and synthetic rates of ATP) as measured in both hepatic and cardiac mitochondria with two substrates pyruvate plus malate and succinate in the presence of rotenone were not significantly (P greater than 0.05) affected by the different dietary concentrations of linoleic acid. The findings indicate a slow turnover of EFA and a low desaturation/elongation activity of the associated enzymes in the pig.