Biomedical subjects

Jose Donato

Publications and source records attributed to Jose Donato.

3 recordsLinked to original sources

PubMed2025

A consensus guide to preclinical indirect calorimetry experiments.

Understanding the complex factors influencing mammalian metabolism and body weight homeostasis is a long-standing challenge requiring knowledge of energy intake, absorption and expenditure. Using measurements of respiratory gas exchange, indirect calorimetry can provide non-invasive estimates of whole-body energy expenditure. However, inconsistent measurement units and flawed data normalization methods have slowed progress in this field. This guide aims to establish consensus standards to unify indirect calorimetry experiments and their analysis for more consistent, meaningful and reproducible results. By establishing community-driven standards, we hope to facilitate data comparison across research datasets. This advance will allow the creation of an in-depth, machine-readable data repository built on shared standards. This overdue initiative stands to markedly improve the accuracy and depth of efforts to interrogate mammalian metabolism. Data sharing according to established best practices will also accelerate the translation of basic findings into clinical applications for metabolic diseases afflicting global populations.

Calorimetry, Indirect↗

PubMed2006

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. Thirty-six adult male Wistar rats received the control diet (AIN-93M) (n=12) and two diets supplemented with BCAA (S1: AIN-93M+3.57% BCAA, n=12, and S2: AIN-93M+4.76% BCAA, n=12) for 6 weeks. The training protocol consisted of bouts of swimming exercise (60 min day(-1)) for 6 weeks at intensities close to the lactate threshold. On the last day of the experiment, all groups were trained for 1 h (1H) or were submitted to the exhaustion test (EX). The time to exhaustion did not differ between groups. The groups submitted to the exhaustion test presented a reduction in plasma glucose and an increase in plasma ammonia and blood lactate concentrations compared to the 1H condition. In the 1H condition, hepatic glycogen concentration was significantly higher in group S2 compared to the control diet and S1 groups (132% and 44%, respectively). Group S2 in the 1H condition presented a higher muscle glycogen concentration (45%) compared to the control diet group. In the EX condition, a significantly higher hepatic glycogen concentration was observed for group S2 compared to the control diet and S1 groups (262% and 222%, respectively). Chronic supplementation with BCAA promoted a higher hepatic and muscle glycogen concentration in trained animals, with this effect being dose dependent.

Amino Acids, Branched-Chain↗

PubMed2006

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. METHODS: Adult male Wistar rats were submitted to 50% FR for 6 weeks. The control group received the AIN-93M diet and the leucine group received the same diet supplemented with 5.91 g L-leucine/kg ration. We then determined carcass chemical composition, serum leptin, albumin and total protein concentrations, and protein, DNA and RNA concentrations in gastrocnemius muscle and liver. RESULTS: No difference in final body weight was observed between groups. However, the leucine group presented a lower amount of body fat (P < 0.05). Leptin concentration showed a directly proportional correlation with the amount of body fat (r = 0.88, P < 0.05), but no significant difference in serum leptin concentration was observed between groups (P = 0.08). Regarding protein nutritional status, liver protein concentration was higher in the leucine group (P < 0.05). In the gastrocnemius muscle, a higher RNA concentration (P < 0.05) and a tendency towards higher DNA concentration (P = 0.06) were observed in the leucine group. CONCLUSION: The results indicate that low-dose leucine supplementation increases body fat loss and improves liver protein status and the capacity of muscle protein synthesis in rats submitted to FR.

Adipose Tissue↗