Arterial concentration and net exchange across the leg and splanchnic bed of 19 amino acids were determined in healthy, postabsorptive subjects in the resting state and after 10 and 40 min of exercise on a bicycle ergometer at work intensities of 400, 800, and 1200 kg-m/min. Arterio-portal venous differences were measured in five subjects undergoing elective cholecystectomy. In the resting stat...

The three essential branched-chain amino acids (BCAAs), leucine, isoleucine and valine, share the first enzymatic steps in their metabolic pathways, including a reversible transamination followed by an irreversible oxidative decarboxylation to coenzyme-A derivatives. The respective oxidative pathways subsequently diverge and at the final steps yield acetyl- and/or propionyl-CoA that enter the K...

Jones, A. S., Hepburn, W. R., Cadenhead, A. & Boyne, A. W. (1962). Anim. Prod. 4, 185. McOsker, D. R. (1962).J. Nutr. 76, 453. Miller, D. S. & Payne, P. R. (1959). Brit.J. Nutr. 13, 501. Miller, D. S. & Payne, P. R. (1961). Brit .9. Nutr. 15, 11. Miller, D. S. & Payne, P. R. (1963). J. theor. Bid. 5 , 1398. Milner, C. K. & Carpenter, K. J. (1963). Proc. Nutr. SOC. 22, xxii. Mitchell, H. H. & Bl...

The ciliated protozoan, Tetrahymena geleii, is known to be similar to higher animals in its nutritional requirements. Thus it may utilize glycogen, starch, and galactose, as well as glucose and sucrose for its carbohydrate supply (1). In addition, it requires for optimal growth very nearly all of the B vitamins known at present and all of the amino acids essential to mammalian growth and mainte...

Plasma concentration, splanchnic and renal exchange, and urinary excretion of 20 amino acids were studied in obese subjects during prolonged (5-6 wk) starvation. Splanchnic amino acid uptake was also investigated in postabsorptive and briefly (36-48 hr) fasted subjects.A transient increase in plasma valine, leucine, isoleucine, methionine, and alpha-aminobutyrate was noted during the 1st wk of ...