Serum acylcarnitine profile in endurance horses with and without metabolic dysfunction

This study investigated mitochondrial fatty acid β-oxidation in endurance horses exposed to long-distance exercise. Electrospray tandem mass spectrometry analysis of serum acylcarnitine profiles from 10 Arab horses was performed before and after a 160 km endurance race. Results were analysed statistically using ANOVA.Mean speed over the entire race in finishing horses was 16.7 ± 1.2 km/h. Endurance exercise increased mitochondrial β-oxidation approximately eight-fold (pre-race, 5648.62 ± 1508.52 nmol/L; post-race, 44243.17 ± 11504.45 nmol/L; P=0.001). In these horses, there was an approximately 17-fold increased lipolysis, as demonstrated by elevated serum concentrations of non-esterified fatty acids (NEFA; pre-race, 0.08 ± 0.08 mmol/L; post-race, 1.32 ± 0.36 mmol/L; P<0.001). In comparison, four Arab horses with poor performance showed an approximately five-fold increase in mitochondrial β-oxidation (pre-race, 5286.17 ± 3355.16 nmol/L; post-race, 26660.57 ± 10064.27 nmol/L; P=0.009); there was a 29-fold increase in NEFA (pre-race, 0.02 ± 0.01 mmol/L; post-race, 0.58 ± 0.07 mmol/L; P=0.006) in these horses. Similar post-exercise free carnitine:acetylcarnitine ratios in both groups suggest that the availability of carnitine in long-distance endurance horses might limit performance.
Source: The Veterinary Journal - Category: Veterinary Research Source Type: research