Alterations of fatty acid β-oxidation capability in the liver of ketotic cows

Abstract

Dairy cows are highly susceptible to ketosis after parturition. In the present study, we evaluated the expression of fatty acid β-oxidation-related enzymes in the liver of ketotic (n=6) and nonketotic (n=6) cows. Serum levels of nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), and glucose were determined by using standard biochemical techniques. The mRNA abundance and protein content of acyl-CoA synthetase long-chain (ACSL), carnitine palmitoyltransferase I (CPT I), carnitine palmitoyltransferase II (CPT II), acyl-CoA dehydrogenase long chain (ACADL), 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS), and acetyl-CoA carboxylase (ACC) were evaluated by real-time PCR and ELISA. We found that serum glucose levels were lower in ketotic cows than in nonketotic cows, but serum BHBA and NEFA concentrations were higher. Messenger RNA and protein levels of ACSL were significantly higher in livers of ketotic cows than those in nonketotic cows. In contrast, mRNA levels of CPT I and mRNA and protein levels of CPT II, ACADL, HMGCS, and ACC were decreased in the liver of ketotic cows. Serum NEFA concentration positively correlated with ACSL protein levels and negatively correlated with protein levels of CPT II, HMGCS, ACADL, and ACC. In addition, serum BHBA concentration negatively correlated with protein levels of CPT II, HMGCS, and ACADL. Overall, fatty acid β-oxidation capability was altered in the liver of ketotic compared with nonketotic cows. Furthermore, high serum NEFA and BHBA concentrations play key roles in affecting pathways of fatty acid metabolism in the liver.

Hepatic gene expression involved in glucose and lipid metabolism in transition cows: Effects of fat mobilization during early lactation in relation to milk performance and metabolic changes

“…The absence of such correlations was also seen by van Dorland et al (2009). Interestingly, hepatic HMGCS2 gene and protein expression were reduced in ketotic dairy cows, indicating a negative feedback mechanism due to BHBA plasma concentrations (Li et al, 2012).…”

Blood clinicopathological differences between type I and II ketosis in dairy cows

“…BHBA content reflects the oxidation of fat metabolic, and NEFA content reflects the mobilization of fat. When the contents of BHBA and NEFA increased in the blood, it indicts that there are a lot of mobilization of fat (Li et al, 2012). The dairy cow induced ketosis when the concentration of NEFA product more than the demands of body.…”

Avaliação do perfil metabólico de vacas da raça Holandesa durante o período de transição

“…O BHBA é um dos principais corpos cetônicos produzidos pelo fígado e importante indicador do BEN na vaca (Ospina et al 2010b). O aumento da concentração sérica de corpos cetônicos ocorre quando a quantidade de AGNE excede a capacidade de oxidação pelo fígado (Drackley 1999, Li et al 2012. A interação entre AGNE e BHBA pode ser observada pelo comportamento de suas concentrações na Figura 1.…”

“…LeBlanc et al (2005) observaram aumento de BHBA uma semana antes do parto, refletindo a precoce mobilização de reservas corporais. Como descrito anteriormente, a intensidade do BEN esta relacionada a intensidade de mobilização de AGNE e consequentemente na produção de BHBA (Drackley 1999, Ospina et al 2010b, Li et al 2012.…”