L-glutamine and L-alanine supplementation increase glutamine-GSH axis and muscle HSP-27 in rats trained using a progressive high-intensity resistance exercise
Jaqueline Santos Moreira Leite Physiologie appliquée, nutrition et métabolisme 28 March 2016.
In this study we investigated the chronic effects of oral L-glutamine and L-alanine supplementation, either in their free or dipeptide form, on glutamine-GSH (GLN-GSH) axis and cytoprotection mediated by HSP-27 in rats submitted to resistance exercise (RE). Forty Wistar rats were distributed into five groups: sedentary (SED), trained (CTRL), and trained supplemented with L-alanyl-L-glutamine (DIP), L-glutamine and L-alanine in their free form (GLN+ALA) or free L-alanine (ALA). All trained animals were submitted to a six-week ladder climbing protocol. Supplementations were offered in a 4% drinking water solution for 21 days prior to euthanasia. Plasma glutamine, creatine kinase (CK), myoglobin (MYO), and erythrocyte concentration of reduced glutathione (GSH) and glutathione disulfide (GSSG) were measured. In Tibialis anterior skeletal muscle, GLN-GSH axis, TBARS, and the expression of HSF-1, HSP-27 and glutamine synthetase were determined.
In CRTL animals high intensity RE reduced muscle glutamine levels and increased GSSG/GSH rate and TBARS, as well as augmented plasma CK and MYO levels. Conversely,
L-glutamine supplemented animals showed an increase in plasma and muscle levels of glutamine, with a reduction in GSSG/GSH rate, TBARS and CK. Free L-alanine administration increased plasma glutamine concentration and lowered muscle TBARS. HSF-1 and HSP-27 were high in all supplemented groups, when compared to CTRL (p<0.05).
The results presented herein demonstrate that L-glutamine supplemented with L-alanine, in both a free or dipeptide form, improve the GLN-GSH axis and promote cytoprotective effects in rats submitted to high intensity RE training.