Avaliaram-se o crescimento e a composição dos filés de juvenis de jundiá após 90 dias de alimentação com dietas contendo diferentes fontes protéicas. Foram utilizados 540 peixes, peso inicial=15,0±0,62g; comprimento inicial=11,98±0,35cm, distribuídos ao acaso em 18 tanques (30 peixes/tanque) com sistema de recirculação de água. Foram testadas seis dietas: 1 - farinha de carne e ossos + levedura (CL), 2 - farelo de soja + levedura (SL), 3 - farelo de soja (S), 4 - farinha de carne e ossos + farelo de soja (CS), 5 - farinha de peixe + levedura (PL) e 6 - farinha de peixe + farelo de soja (PS). Avaliaram-se: peso, comprimento total, taxa de crescimento específico, fator de condição, sobrevivência, conversão alimentar aparente, taxa de eficiência protéica e consumo diário. Também foram analisadas as composições do filé - umidade, proteína, lipídios, cinzas -, as taxas de deposição de proteína e gordura, além dos rendimentos de filé e carcaça. Maiores pesos, 111,5 e 108,6g, comprimento total, 22,6 e 21,6cm, e taxa de crescimento específico, 2,1 e 2,2%/dia, foram observados nos peixes alimentados com as dietas CS e PS. Os peixes alimentados com CS e PS também apresentaram maior deposição de proteína, 69,8 e 71,5mg/dia, e lipídios, 77,2 e 78,3mg/dia. A sobrevivência foi menor na dieta PS, 92,9%. Os maiores rendimentos de carcaça foram observados nos peixes alimentados com PS e PL, 82,9 e 82,7%, e o menor rendimento de filé ocorreu na dieta CL, 34,1%.

The growth and fillet composition of jundiá juveniles after 90 days being fed with diets containing different protein sources were evaluated. Five hundred and forty fish (initial weight: 15.00±0.62g; initial length: 11.98±0.35cm) were randomly distributed in 18 tanks (30 fish/tank), in a water re-use system. Six diets were tested: 1- meat and bone meal + yeast (CL), 2- soybean meal + yeast (SL), 3- soybean meal (S), 4- meat and bone meal + soybean meal (CS), 5- fish meal + yeast (PL,) and 6- fish meal + soybean meal (PS). The following parameters were evaluated: weight, total length, specific growth rate, condition factor, survival, feed conversion ratio, protein efficiency ratio, and daily consumption. Fillet composition (moisture, protein, lipid, and ash), protein and lipid depositions ratios, carcass and fillet yields were also determined. The highest values of weight (111.5 and 108.6g), total length (22.6 and 21.6cm), and specific growth rate (2.1 and 2.2%/day), were observed in fish fed CS and PS diets. Fish fed CS and PS diets also showed the highest protein (69.8 and 71.5mg/day), and lipid depositions (77.2 and 78.3mg/day). Survival was smaller in fish fed diet PS (92.86%). The highest values of carcass yield were observed in fish fed PL and PS diets (82.9 and 82.7%), and the lower fillet yield was observed in CL diet (34.1%).

Adenosine 5',5'''-P1,P4-tetraphosphate (Ap4A) and adenosine 5',5'''-P1,P5-pentaphosphate (Ap5A) are stored in and released from rat brain synaptic terminals. In the present study we investigated the hydrolysis of dinucleotides (Ap4A and Ap5A) in synaptosomes from the cerebral cortex of adult rats. Ap4A and Ap5A, but not Ap3A, were hydrolyzed at pH 7.5 in the presence of 20 mM Tris/HCl, 2.0 mM MgCl2, 10 mM glucose and 225 mM sucrose at 37oC. The disappearance of the substrates measured by FPLC on a mono-Q HR column was both time and protein dependent. Since synaptosome integrity was at least 90% at the end of the assay, hydrolysis probably occurred by the action of an ecto-enzyme. Extracellular actions of adenine dinucleotides at central nervous system terminate due to the existence of ecto-nucleotidases which specifically cleave these dinucleotides. These enzymes in association with an ATP diphosphohydrolase and a 5'-nucleotidase are able to promote the complete hydrolysis of dinucleotides to adenosine in the synaptic cleft.