Metabolic adjustments of Dentex dentex to prolonged starvation and refeeding

• Tipo: Artigo em Revista Científica Internacional
• Data: 2012

Autores

perez-jimenez, a. (Autor) FCUP; cardenete, g. (Autor) Outra; hidalgo, m. c. (Autor) Outra; garcia-alcazar, a. (Autor) Outra; abellan, e. (Autor) Outra; morales, a. e. (Autor) Outra

Revista

Título: Fish Physiology and Biochemistry

Vol. 38

Páginas: 1145-1157

ISSN: 0920-1742

Editora: Springer Nature

Indexação

ISI Web of Knowledge - 4 Citações

Scopus - 5 Citações

Outras Informações

ID Authenticus: P-002-7P4

DOI: 10.1007/s10695-011-9600-2

Abstract (EN): The particular metabolic strategies of the common dentex (Dentex dentex) to face a period of prolonged starvation and subsequent refeeding were assessed. Plasma metabolites, endogenous reserves, and the activity of key enzymes of intermediary metabolism in liver, white muscle, and heart were evaluated. Plasma glucose, total lipid, triglycerides, total-, HDL- and LDL-cholesterol, and protein levels, liver, and white muscle glycogen, and perivisceral, and muscle fat were significantly reduced by starvation, whereas liver lipid content was surprisingly increased. Those enzymes involved in phosphorylation and oxidation of glucose and lipid synthesis, as well as alanine aminotransferase activity, were significantly depressed in liver of starved fish. The increase in beta-hydroxyacyl-CoA dehydrogenase (HOAD) indicated an enhanced fatty acid oxidation during starvation. Part of the acetyl-CoA generated by beta-oxidation was oxidized in the hepatic Krebs cycle, as reflected the increased citrate synthase (CS) activity. The oxaloacetate required for the reaction catalized by CS activity would be supplied by aspartate aminotransferase (ASAT) activity whose activity was also enhanced. Glutamate dehydrogenase also increased to deaminate the glutamate produced by transaminases, especially by the increased ASAT activity. Liver gluconeogenesis of starved fish was maintained at the same rate that in controls, with glycerol playing an important role as glucogenic substrate. The increased hepatic beta-hydroxybutyrate dehydrogenase (beta-OHBDH) activity indicates that part of the acetyl-CoA arriving from beta-oxidation was being diverted for ketone bodies production with dentex liver playing an important role in providing ketone bodies as fuels for other tissues under such circumstances. Most enzyme activities in white muscle of starved dentex were significantly depressed. In heart, starvation induced an important inhibition of those enzymes involved in glucose and protein metabolism, whereas CS, HOAD, and beta-OHBDH activities were maintained at control levels. Although several biomarkers assayed returned to control values after refeeding, many others did not, which indicate that after 3 weeks of refeeding, pre-starved dentex is still experiencing a transient period of metabolic adjustments directed toward the restoration of body mass.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 13