Plasma and liver carnitine (free and esterified) levels and their interrelationships in moderately hypercholesterolemic monkeys (Macaca arctoides)

The level of carnitine and its esters was measured in plasma and liver in 20 male stump-tailed monkeys (Macaca arctoides) that were fed a moderately hypercholesterolemic diet. Plasma total carnitine was 60 +/- 3 nmol/mL (30% esterified) and liver total carnitine was 254 +/- 15 nmol/g wet weight (16% esterified) or 1.28 +/- 0.07 nmol/mg noncollagen protein. The plasma concentration of total carnitine was positively correlated with the total carnitine concentration of the livers (r = 0.71, p less than 0.001). Additionally, there was a positive correlation between plasma esterified carnitine and liver esterified carnitine (r = 0.92, p less than 0.001) as well as between plasma esterified carnitine and plasma beta-hydroxybutyrate (r = 0.92, p less than 0.001), which together suggest that plasma esterified carnitine in the monkeys was largely of hepatic origin. There was no significant correlation between plasma carnitine (total, free, or esterified) and body mass, plasma triglycerides, or plasma cholesterol.