title: Oral supplementations with L-glutamine or L-alanyl-L-glutamine do not change metabolic alterations induced by long-term high-fat diet in the B6.129F2/J mouse model of insulin resistance.
abstract: In this work, we aimed to investigate the effects of long-term supplementations with L-glutamine or L-alanyl-L-glutamine in the high-fat diet (HFD)-fed B6.129SF2/J mouse model over insulin sensitivity response and signaling, oxidative stress markers, metabolism and HSP70 expression. Mice were fed in a standard low-fat diet (STA) or a HFD for 20 weeks. In the 21th week, mice from the HFD group were allocated in five groups and supplemented for additional 8 weeks with different amino acids: HFD control group (HFD-Con), HFD + dipeptide L-alanyl-L-glutamine group (HFD-Dip), HFD + L-alanine group (HFD-Ala), HFD + L-glutamine group (HFD-Gln), or the HFD + L-alanine + L-glutamine (in their free forms) group (HFD-Ala + Gln). HFD induced higher body weight, fat pad, fasted glucose, and total cholesterol in comparison with STA group. Amino acid supplementations did not induce any modifications in these parameters. Although insulin tolerance tests indicated insulin resistance in all HFD groups, amino acid supplementations did not improve insulin sensitivity in the present model. There were also no significant differences in the immunocontents of insulin receptor, Akt, and Toll-like receptor-4. Notably, total 70 kDa heat shock protein (HSP72 + HSP73) contents in the liver was markedly increased in HFD-Con group as compared to STA group, which might suggest that insulin resistance is only in the beginning. Apparently, B6.129SF2/J mice are more resistant to the harmful effects of HFD through a mechanism that may include gut adaptation, reducing the absorption of nutrients, including amino acids, which may explain the lack of improvements in our intervention.
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Patricia Martins
authors.initials: PM
authors.lastname: Bock
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Krause
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Helena Trevisan
authors.initials: HT
authors.lastname: Schroeder
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Gabriela Fernandes
authors.initials: GF
authors.lastname: Hahn
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Hilton Kenji
authors.initials: HK
authors.lastname: Takahashi
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Cinthia Maria
authors.initials: CM
authors.lastname: Schöler
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Graziella
authors.initials: G
authors.lastname: Nicoletti
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Luiz Domingos Zavarize
authors.initials: LD
authors.lastname: Neto
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Maria Inês Lavina
authors.initials: MI
authors.lastname: Rodrigues
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil.
authors.forename: Maciel Alencar
authors.initials: MA
authors.lastname: Bruxel
authors.affiliation: Laboratory of Cellular Physiology, Department of Physiology, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Rua Sarmento Leite, 500, 2nd floor, suite 350, Porto Alegre, RS, 90050-170, Brazil. pauloivo@ufrgs.br.
authors.forename: Paulo Ivo
authors.initials: PI
authors.lastname: Homem de Bittencourt
mesh_terms: D000284:Administration, Oral; D000818:Animals; D059305:Diet, High-Fat; D004195:Disease Models, Animal; D005973:Glutamine / Q000008:administration & dosage* / Q000031:analogs & derivatives; D007333:Insulin Resistance; D051379:Mice
chemical_list: D005973:Glutamine
keywords: Alanyl-glutamine; Glutamine; HSP70; High-fat diet; Insulin resistance; Obesity