Lysine metabolism across the hindquarters of sheep; effect of intake on transfers from plasma and red blood cells

• Published in: British journal of nutrition 2001-05, Vol.85 (5), p.565-573
• Main Authors: Savary, Isabelle C., Hoskin, Simone O., Dennison, Ngaire, Lobley, Gerald E.
• Format: Article
• Language: English
• Subjects: Amino acids; Analysis of Variance; Animals; Biological and medical sciences; Biological Transport; Blood; Catheters; Coronary vessels; Diet; Erythrocytes; Erythrocytes - metabolism; Feeding. Feeding behavior; Food and Nutrition; Fundamental and applied biological sciences. Psychology; Gas Chromatography-Mass Spectrometry; Hindlimb - metabolism; Hindquarters; Life Sciences; Lysine; Lysine - metabolism; Lysine - pharmacokinetics; Male; Metabolism; Nutrition; Plasma; Protein synthesis; Proteins; Red blood cells; Sheep; Sheep - metabolism; Splanchnic Circulation; Tissues; Veins & arteries; Vertebrates: anatomy and physiology, studies on body, several organs or systems
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN2000318

Both plasma and red blood cells contain amino acids (AA), but the relative amount of AA transferred from each vascular compartment to the tissues remains unclear. For splanchnic tissues, the relative transfers between the plasma, the red blood cells and the tissues may vary with nutritional state, but whether the same situation pertains for other tissues is not known. The current study focused on the transfer of lysine from plasma and red blood cells across the hindquarters of sheep offered four levels of intakes (0.5, 1.0, 1.5 and 2.5×maintenance energy). This design, coupled with use of [U-13C]lysine as tracer, also allowed the effect of intake on protein kinetics to be examined. At all intakes, the concentration of lysine in the sheep’ red blood cells exceeded that in plasma by 50 % (P