Genes diferencialmente expressos em cana-de-açúcar inoculada com Xanthomonas albilineans, o agente causal da escaldadura da folha

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Atividade alelopática de Copaifera langsdorffii DESF: abordagem fitoquímica e molecular

Pós-graduação em Ciências Biológicas (Botânica) - IBB

Overexpression of the activated form of the AtAREB1 gene (AtAREB1 Delta QT) improves soybean responses to water deficit

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of leucine supplemented diet on intestinal absorption in tumor bearing pregnant rats

Background: It is known that amino acid oxidation is increased in tumor-bearing rat muscles and that leucine is an important ketogenic amino acid that provides energy to the skeletal muscle.Methods: To evaluate the effects of a leucine supplemented diet on the intestinal absorption alterations produced by Walker 256, growing pregnant rats were distributed into six groups. Three pregnant groups received a normal protein diet (18% protein):pregnant (N), tumor-bearing (WN), pair-fed rats (Np). Three other pregnant groups were fed a diet supplemented with 3% leucine (15% protein plus 3% leucine):leucine (L), tumor-bearing (WL) and pair-fed with leucine (Lp). Non pregnant rats (C), which received a normal protein diet, were used as a control group. After 20 days, the animals were submitted to intestinal perfusion to measure leucine, methionine and glucose absorption.Results: Tumor-bearing pregnant rats showed impairment in food intake, body weight gain and muscle protein content, which were less accentuated in WL than in WN rats. These metabolic changes led to reduction in both fetal and tumor development. Leucine absorption slightly increased in WN group. In spite of having a significant decrease in leucine and methionine absorption compared to L, the WL group has shown a higher absorption rate of methionine than WN group, probably due to the ingestion of the leucine supplemented diet inducing this amino acid uptake. Glucose absorption was reduced in both tumor-bearing groups.Conclusions: Leucine supplementation during pregnancy in tumor-bearing rats promoted high leucine absorption, increasing the availability of the amino acid for neoplasic cells and, mainly, for fetus and host utilization. This may have contributed to the better preservation of body weight gain, food intake and muscle protein observed in the supplemented rats in relation to the non-supplemented ones.

Effects of a leucine-rich diet on body composition during nutritional recovery in rats

OBJECTIVE: Protein malnutrition is characterized by a number of morphologic and physiologic alterations, including intestinal mucosal atrophy and impaired nutrient absorption. Impaired absorption accentuates nutritional deficiency and accelerates body weight loss and changes in body chemistry. Because leucine is a ketogenic and oxidative amino acid and stimulates the protein synthesis, we examined the ability of young rats to recover from protein malnutrition by feeding them a control balanced or a leucine-rich diet for 60 d.METHODS: At the end of the 60-d period, body, liver, and muscle weights; glucose, methionine, and leucine intestinal absorption; and carcass chemical composition were evaluated.RESULTS: Body weight gain was higher in the control balanced and leucine-rich groups than in control rats, indicating that adequate refeeding allows body weight to recover in these groups. Methionine and glucose absorptions were impaired in malnourished rats but were restored after nutritional recovery. The leucine-rich diet resulted in an increase in carcass collagen nitrogen but maintained the carcass structural nitrogen.CONCLUSIONS: These results indicated that leucine supplementation during nutritional recovery from protein malnutrition improves protein carcass restoration. However, the precise mechanism of the leucine effects involved in this response remains to be elucidated.

Leucine Supplementation Augments Insulin Secretion in Pancreatic Islets of Malnourished Mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Leucine-rich diet alters the eukaryotic translation initiation factors expression in skeletal muscle of tumour-bearing rats

Background: Cancer-cachexia induces a variety of metabolic disorders on protein turnorver, decreasing protein synthesis and increasing protein degradation. Controversly, insulin, other hormones, and branched-chain amino acids, especially leucine, stimulate protein synthesis and modulate the activity of translation initiation factors involved in protein synthesis. Since the tumour effects are more pronounced when associated with pregnancy, ehancing muscle-wasting proteolysis, in this study, the influence of a leucine-rich diet on the protein synthesis caused by cancer were investigated. Methods: Pregnant rats with or without Walker 256 tumour were distributed into six groups. During 20 days of experiment, three groups were fed with a control diet: C - pregnant control, W - tumour-bearing, and P - pair-fed, which received the same amount of food as ingested by the W group; three other groups of pregnant rats were fed a leucine-rich diet: L - pregnant leucine, WL - tumour-bearing, and PL - pair-fed, which received the same amount of food as ingested by the WL group. Results: The gastrocnemius muscle of WL rats showed increased incorporation of leucine in protein compared to W rats; the leucine-rich diet also prevented the decrease in plasma insulin normally seen in W. The expression of translation initiation factors increased when tumour-bearing rats fed leucine-rich diet, with increase of ∼35% for eIF2α and eIF5, ∼17% for eIF4E and 20% for eIF4G; the expression of protein kinase S6K1 and protein kinase C was also highly enhanced. Conclusion: The results suggest that a leucine-rich diet increased the protein synthesis in skeletal muscle in tumour-bearing rats possibly through the activation of eIF factors and/or the S6kinase pathway. © 2007 Ventrucci et al; licensee BioMed Central Ltd.

Diversidade genética de espécies de Xanthomonas patogênicas a citros baseada em genes avr e leucine protein

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Genetic Diversity of a Brazilian Strain Collection of Xanthomonas citri subsp citri Based on the Type III Effector Protein Genes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First polymorphisms in JY-1 gene in cattle (Bos taurus indicus) and their association with sexual precocity and growth traits

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Formulação de rações para poedeiras com base em aminoácidos totais e digestíveis utilizando diferentes estimativas da composição de aminoácidos em alimentos

Foram utilizadas poedeiras comerciais com 27 semanas de idade, distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3 x 3, com três repetições de seis aves por tratamento. Os fatores consistiram de três métodos de estimativa da composição de aminoácidos em ingredientes (tabelas brasileiras, equações de predição e fator para correção de aminoácido em função do teor de proteína do ingrediente) e três recomendações de aminoácidos, sendo duas de aminoácidos digestíveis e uma de aminoácidos totais. Os métodos de estimativa da composição de aminoácidos nos ingredientes afetaram apenas a conversão alimentar e a espessura de casca, que apresentaram os melhores resultados com a utilização das tabelas brasileiras. Embora as recomendações de aminoácidos tenham determinado diferenças em todos os parâmetros de desempenho, não afetaram a qualidade dos ovos. O desempenho das aves foi prejudicado pelos níveis de aminoácidos digestíveis, entretanto, ambas as recomendações promoveram desempenho semelhante e inferior ao de aminoácidos totais. O pior desempenho das aves alimentadas com as rações formuladas com aminoácidos digestíveis pode ser atribuído à deficiência em nitrogênio para a síntese de aminoácidos não-essenciais, visto que o nível protéico foi reduzido (12,5% PB), ou ainda à deficiência nos aminoácidos arginina, histidina, isoleucina, leucina e valina, cujos requerimentos mínimos não foram considerados na formulação das rações.

Digestibilidade do extrato de leveduras em frangos de corte

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functional alterations in endocrine pancreas of rats with different degrees of dexamethasone-induced insulin resistance

Objectives: We have analyzed the peripheral insulin and glucose sensitivity in vivo, and islet function ex vivo in rats with different degrees of insulin resistance induced by dexamethasone (DEX).Methods: Dexamethasone, in the concentrations of 0.1 (DEX 0.1), 0.5 (DEX 0.5), and 1.0 mg/kg body weight (DEX 1.0) was administered daily, intraperitoneally, to adult Wistar rats for 5 days, whereas controls received saline.Results: Dexamethasone treatment induced peripheral insulin resistance in a dose-dependent manner. At the end of the treatment, only DEX 1.0 rats showed significant increase of postabsorptive blood glucose and serum triglycerides, and nonesterified fatty acids levels. Incubation of pancreatic islets in increasing glucose concentrations (2.8-22 mM) led to an augmented insulin secretion in all DEX-treated rats. Leucine, carbachol, and high KCl concentrations induced the insulin release in DEX 0.5 and DEX 1.0, whereas arginine augmented secretion in all DEX-treated groups.Conclusions: We demonstrate that in DEX 0.5 and, especially in DEX 0.1 groups, but not in DEX 1.0, the adaptations that occurred in the endocrine pancreas are able to counteract metabolic disorders (glucose intolerance and dyslipidemia). These animal models seem to be interesting approaches for the study of degrees of subjacent effects that may mediate type 2 diabetes (DEX 1.0) and islet function alterations, without collateral effects (DEX 0.1 and DEX 0.5).

Digestibilidade aparente do triticale para a tilápia-do-nilo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)