02302naa a2200325 a 450000100080000000500110000800800410001902400320006010000190009224501550011126000090026652013590027565000120163465000120164665000090165865000190166765000150168665000100170165000110171165000160172265000140173865000100175265000130176270000210177570000200179670000150181670000200183170000150185177301100186620584282016-12-12       2016    bl uuuu     u00u1 u    #d7 a10.1590/1678-4162-83372DOI1 aMELO, J. F. B.  aGlycolysis and gluconeogenesis in the liver of catfish fed with different concentrations of proteins, lipids and carbohydrates.h[electronic resource]  c2016  aThe activities of enzymes from a number of metabolic pathways have been used as a tool to evaluate the best use of nutrients on fish performance. In the present study the catfish Rhamdia quelen was fed with diets containing crude protein-lipid-carbohydrate (%) as follows: treatment (T) T1: 19-19-44; T2: 26-15-39; T3: 33-12-33; and T4: 40-10-24. The fish were held in tanks of re-circulated, filtered water with controlled temperature and aeration in 2000L experimental units. The feeding experiment lasted 30 days. The following enzymes of the carbohydrate metabolism were determined: Glucokinase (GK), Phosphofructokinase 1 (PFK-1), Pyruvate kinase (PK), Fructose-1,6-biphosphatase 1 (FBP-1). The activities of 6 phosphogluconate dehydrogenase (6PGDH) and glucose 6 phosphate dehydrogenase (G6PDH) were also assayed. The influence of nutrient levels on the enzyme activities is reported. The increase of dietary protein plus reduction of carbohydrates and lipids attenuates the glycolytic activity and induces hepatic gluconeogenesis as a strategy to provide metabolic energy from amino acids. The fish performance was affected by the concentrations of protein, lipid and carbohydrates in the diet. The greatest weight gain was obtained in fish fed diet T4 containing 40.14% of crude protein, 9.70% of lipids, and 24.37% of carbohydrate, respectively.  aCatfish  aEnzymes  aFish  aFish nutrition  aMetabolism  aBagre  aEnzima  aMetabolismo  aNutriente  aPeixe  aProteina1 aLUNDSTEDT, L. M.1 aINOUE, L. A. K.1 aMETÓN, I.1 aBAANANTE, I. V.1 aMORAES, G.  tArquivo Brasileiro de Medicina Veterinária e Zootecnia, Belo Horizontegv. 68, n. 5, p. 1251-1258, 2016.