title: Effects of supplementation with free glutamine and the dipeptide alanyl-glutamine on parameters of muscle damage and inflammation in rats submitted to prolonged exercise.
abstract: In this study, we investigated the effect of the supplementation with the dipeptide L-alanyl-L-glutamine (DIP) and a solution containing L-glutamine and L-alanine on plasma levels markers of muscle damage and levels of pro-inflammatory cytokines and glutamine metabolism in rats submitted to prolonged exercise. Rats were submitted to sessions of swim training for 6 weeks. Twenty-one days prior to euthanasia, the animals were supplemented with DIP (n = 8) (1.5 g.kg(-1)), a solution of free L-glutamine (1 g.kg(-1)) and free L-alanine (0.61 g.kg(-1)) (G&A, n = 8) or water (control (CON), n = 8). Animals were killed at rest before (R), after prolonged exercise (PE-2 h of exercise). Plasma concentrations of glutamine, glutamate, tumour necrosis factor-alpha (TNF-alpha), prostaglandin E2 (PGE2) and activity of creatine kinase (CK), lactate dehydrogenase (LDH) and muscle concentrations of glutamine and glutamate were measured. The concentrations of plasma TNF-alpha, PGE2 and the activity of CK were lower in the G&A-R and DIP-R groups, compared to the CON-R. Glutamine in plasma (p < 0.04) and soleus muscle (p < 0.001) was higher in the DIP-R and G&A-R groups relative to the CON-R group. G&A-PE and DIP-PE groups exhibited lower concentrations of plasma PGE2 (p < 0.05) and TNF-alpha (p < 0.05), and higher concentrations of glutamine and glutamate in soleus (p < 0.001) and gastrocnemius muscles (p < 0.05) relative to the CON-PE group. We concluded that supplementation with free L-glutamine and the dipeptide LL-alanyl-LL-glutamine represents an effective source of glutamine, which may attenuate inflammation biomarkers after periods of training and plasma levels of CK and the inflammatory response induced by prolonged exercise.
authors.affiliation: Department of Food Science and Experimental Nutrition, University of São Paulo, Brazil.
authors.forename: Vinicius Fernandes
authors.initials: VF
authors.lastname: Cruzat
authors.forename: Marcelo Macedo
authors.initials: MM
authors.lastname: Rogero
authors.forename: Julio
authors.initials: J
authors.lastname: Tirapegui
mesh_terms: D000409:Alanine / Q000494:pharmacology; D000818:Animals; D003402:Creatine Kinase / Q000097:blood / Q000378:metabolism; D019587:Dietary Supplements; D015232:Dinoprostone / Q000097:blood; D004151:Dipeptides / Q000494:pharmacology*; D018698:Glutamic Acid / Q000097:blood; D005973:Glutamine / Q000097:blood / Q000494:pharmacology*; D018836:Inflammation Mediators / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000097:blood / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D010805:Physical Conditioning, Animal; D051381:Rats; D017208:Rats, Wistar; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D004151:Dipeptides; D018836:Inflammation Mediators; D014409:Tumor Necrosis Factor-alpha; D005973:Glutamine; D018698:Glutamic Acid; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase; D015232:Dinoprostone; D000409:Alanine; C054122:alanylglutamine