KEY ENZYMES AND NUCLEAR RECEPTORS OF HEPATIC LIPID METABOLISM IN DAIRY CATTLE DURING THE TRANSITION PERIOD

GAREIS, N.C.; ORTEGA, H.H.; ANGELI, E.; MARELLI, B.E.; TRIONFINI V.; HEIN, G.J.

Mar del Plata

Congreso; LXI REUNIÓN ANUAL DE LA SOCIEDAD ARGENTINA DE INVESTIGACIÓN CLÍNICA; 2016

The transition period (TP) is the most critical in the lactation of a dairycow, characterized by a negative energy balance leading to an important lipidmobilization, with increases in the systemic non-esterified fatty acids (NEFA)and beta-hydroxybutyric (BHB) concentrations. The aim of this study was toevaluate some pathways of hepatic lipid metabolism during the TP. Blood samplesand liver biopsies (n=10) at 28 and 14 days prepartum were taken, and also at4, 14, 28 and 60 days postpartum. Systemic NEFA, BHB, glucose and insulin concentrationswere measured. Besides, the liver expressions of fatty acid oxidation (CPT1,ACOX1) and re-esterification enzymes (DGAT1), and nuclear receptor PPAR-α wereevaluated by RT-PCR and western blot. There were no significant changes (p>0.05) in glycemia and insulinemia. Differences in the BHB and NEFAconcentrations were observed at different sampling days, being significant at4, 14 and 30 days postpartum (p <0.05). The expressions of CPT1 and PPARαwere higher in the postpartum period (p <0.05), with an opposite behaviorrespect the expression of DGAT1. No differences in the mRNA expression of ACOX1were observed. These results show significant changes in hepatic lipidmetabolism of dairy cows during the TP. These knowledge could represent a usefultool to understand the metabolic behavior in animals with different milk productionand to optimize the health of dairy cattle during this period.