Leucine supplementation increases serum insulin-like growth factor 1 concentration and liver protein/RNA ratio in rats after a period of nutritional recovery.

This study evaluated the effect of leucine on the protein status of rats submitted to 50% food restriction for 1 week, followed by 2 weeks of nutritional recovery. A significant increase of serum insulin-like growth factor 1 and protein/RNA ratio in the liver was observed in leucine-supplemented rats. There was no change in carcass, liver, or gastrocnemius protein content when compared with control animals.

Effects of diets supplemented with branched-chain amino acids on the performance and fatigue mechanisms of rats submitted to prolonged physical exercise.

This study aimed to determine the effects of diets chronically supplemented with branched-chain amino acids (BCAA) on the fatigue mechanisms of trained rats. Thirty-six adult Wistar rats were trained for six weeks. The training protocol consisted of bouts of swimming exercise (one hour a day, five times a week, for six weeks).

Effects of two different levels of dietary protein on body composition and protein nutritional status of growing rats.

This study aimed to investigate the effect of a high-protein diet on growth, body composition, and protein nutritional status of young rats. Newly-weaned Wistar rats, weighing 45-50 g, were distributed in two experimental groups, according to their diets, which contained 12% (G12) or 26% protein (G26), over a period of 3 weeks. The animals were euthanized at the end of this period and the following analyses were performed: chemical composition of the carcass, proteoglycan synthesis, IGF-I concentration (serum, muscle and cartilage), total tissue RNA, protein concentration (muscle and cartilage) and protein synthesis (muscle and cartilage).

Effects of dietary glutamine supplementation on the body composition and protein status of early-weaned mice inoculated with Mycobacterium bovis Bacillus Calmette-Guerin.

Glutamine, one of the most abundant amino acids found in maternal milk, favors protein anabolism. Early-weaned babies are deprived of this source of glutamine, in a period during which endogenous biosynthesis may be insufficient for tissue needs in states of metabolic stress, mainly during infections. The objective of this study was to verify the effects of dietary glutamine supplementation on the body composition and visceral protein status of early-weaned mice inoculated with Mycobacterium bovis Bacillus Calmette-Guérin (BCG).

Leucine supplementation favors liver protein status but does not reduce body fat in rats during 1 week of food restriction.

An important role in protein-energy metabolism has been attributed to leucine because of its long-term effects on body fat reduction and on the improvement of some indicators of protein status in rodents. The present study investigated the influence of leucine supplementation on the body composition and protein status of rats during the early phase of weight loss, which is characterized by a rapid loss of body weight. Thirty adult male Wistar rats were divided into 2 groups, a control and a leucine group (diet supplemented with 0.

Dietary glutamine supplementation increases the activity of peritoneal macrophages and hemopoiesis in early-weaned mice inoculated with Mycobacterium bovis bacillus Calmette-Guérin.

Infants who are breast-fed have been shown to have a lower incidence of certain infectious diseases compared with formula-fed infants. Glutamine is one of the most abundant amino acids found in maternal milk and it is essential for the function of immune system cells such as macrophages. The purpose of this study was to investigate the effect of glutamine supplementation on the function of peritoneal macrophages and on hemopoiesis in early-weaned mice inoculated with Mycobacterium bovis bacillus Calmette-Guérin (BCG).

Effects of leucine and phenylalanine supplementation during intermittent periods of food restriction and refeeding in adult rats.

Although many studies have shown that amino acid ingestion acutely stimulates protein anabolism, only few studies have investigated whether long-term supplementation promotes changes in body composition. We therefore tested the hypothesis that l-leucine (LEU) and l-phenylalanine (PHE) supplementation might have a positive impact on the body composition of rats submitted to intermittent periods of food restriction and refeeding (weight cycling or WC). The WC protocol comprised three cycles, each consisting of 1 week of 50% food restriction followed by 2 weeks of ad libitum ingestion.

Effect of chronic supplementation with branched-chain amino acids on the performance and hepatic and muscle glycogen content in trained rats.

The objective of this study was to evaluate the effects of a diet supplemented with branched-chain amino acids (BCAA; 3.57% and 4.76%) on the performance and glycogen metabolism of trained rats.

Effects of leucine supplementation on the body composition and protein status of rats submitted to food restriction.

Objective: Acute administration of leucine has been shown to stimulate certain protein synthesis related anabolic processes. However, the effect of chronic leucine administration in a catabolic situation caused by food restriction (FR) has not been established. We therefore evaluated the effect of chronic leucine supplementation on the body composition and some indicators of protein nutritional status of rats submitted to FR.

Effect of alanyl-glutamine supplementation on plasma and tissue glutamine concentrations in rats submitted to exhaustive exercise.

Objective: We investigated the effect of supplementation with L-glutamine and L-alanyl-L-glutamine (DIP) on the plasma and tissue glutamine concentrations of exercise-trained rats immediately and 3 hours after a single exercise session until exhaustion.

Methods: Thirty-six male rats were divided into six groups, and then subdivided into groups submitted only to the exhaustion test: control (CON-EXA, n = 6), glutamine (GLN-EXA, n = 6) and DIP-EXA (n = 6), or to the exhaustion test followed by a recovery period lasting 3 hours: control (CON-REC, n = 6), glutamine (GLN-REC, n = 6) and DIP-REC (n = 6). The training protocol consisted of bouts of swimming exercise (60 min x day(-1)) for 6 weeks.