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

• Published in: Molecular and cellular biochemistry Vol. 411; no. 1-2; pp. 351 - 362
• Main Authors: Bock, Patricia Martins, Krause, Mauricio, Schroeder, Helena Trevisan, Hahn, Gabriela Fernandes, Takahashi, Hilton Kenji, Schöler, Cinthia Maria, Nicoletti, Graziella, Neto, Luiz Domingos Zavarize, Rodrigues, Maria Inês Lavina, Bruxel, Maciel Alencar, Homem de Bittencourt, Paulo Ivo
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.01.2016; Springer Nature B.V
• Subjects: Administration, Oral; Amino acids; Animals; Biochemistry; Biomedical and Life Sciences; Body weight; Cardiology; Diet; Diet, High-Fat; Disease Models, Animal; Glutamine - administration & dosage; Glutamine - analogs & derivatives; Insulin Resistance; Life Sciences; Medical Biochemistry; Metabolism; Mice; Obesity; Oils & fats; Oncology; Oxidative stress; Obesity; Insulin resistance; HSP70; High-fat diet; Alanyl-glutamine; Glutamine
• ISSN: 0300-8177; 1573-4919
• DOI: 10.1007/s11010-015-2597-6

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.