A dipeptide and an amino acid present in whey protein hydrolysate increase translocation of GLUT-4 to the plasma membrane in Wistar rats

• Published in: Food chemistry Vol. 139; no. 1-4; pp. 853 - 859
• Main Authors: Morato, P.N., Lollo, P.C.B., Moura, C.S., Batista, T.M., Carneiro, E.M., Amaya-Farfan, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15-08-2013; Elsevier
• Subjects: amino acids; Amino Acids - analysis; Amino Acids - metabolism; Animals; Biological and medical sciences; blood glucose; Branched-chain amino acids; Cell Membrane - metabolism; Dipeptides - analysis; Dipeptides - metabolism; Food industries; free amino acids; Fundamental and applied biological sciences. Psychology; glucose; Glucose - metabolism; Glucose transporter; Glucose Transporter Type 4 - metabolism; glucose transporters; glycogen; Glycogen - metabolism; l-Isoleucine; l-Leucyl-l-isoleucine; Male; Milk and cheese industries. Ice creams; Milk Proteins - chemistry; Milk Proteins - metabolism; Muscle, Skeletal - metabolism; Peptides; plasma membrane; protein hydrolysates; Protein Hydrolysates - chemistry; Protein Hydrolysates - metabolism; Protein Transport; Rats; Rats, Wistar; skeletal muscle; Western blotting; whey protein; Whey Proteins; Glucose transporter; AST; Peptides; l-Isoleucine; CK; ALT; Akt; p85; UC; WPH; LDH; l-Leucyl-l-isoleucine; Branched-chain amino acids; GLUT-4; AMPK; PM; Rat; L-Leucyl-L-isoleucine; Rodentia; Glucose; L-Isoleucine; Branched chain; Milk protein; Vertebrata; Mammalia; Hydrolysate; Plasma membrane; Dipeptides; Carbohydrate; Whey protein
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2012.12.062

► l-Isoleucine increased GLUT-4 translocation to the plasmatic membrane. ► l-Leucyl-l-isoleucine increased GLUT-4 translocation to the plasmatic membrane. ► l-Leucyl-l-isoleucine caused the highest insulinotropic effect. ► l-Isoleucine reduced the blood glucose levels, without increasing the insulin levels.
Whey protein hydrolysate (WPH) is capable of increasing muscle glycogen reserves and of concentrating the glucose transporter in the plasma membrane (PM). The objective of this study was to determine which WPH components could modulate translocation of the glucose transporter GLUT-4 to the PM of animal skeletal muscle. Forty-nine animals were divided into 7 groups (n=7) and received by oral gavage 30% glucose plus 0.55g/kg body mass of the following WPH components: (a) control; (b) WPH; (c) l-isoleucine; (d) l-leucine; (e) l-leucine plus l-isoleucine; (f) l-isoleucyl-l-leucine dipeptide; (g) l-leucyl-l-isoleucine dipeptide. After receiving these solutions, the animals were sacrificed and the GLUT-4 analysed by western blot. Additionally, glycogen, glycaemia, insulin and free amino acids were also determined by standard methods. Of the WPH components tested, the amino acid l-isoleucine and the peptide l-leucyl-l-isoleucine showed greater efficiency in translocating GLUT-4 to the PM and of increasing glucose capture by skeletal muscle.