Normal human volunteers were intubated with either aspiration tubes or a biopsy capsule placed in the small intestine. The subjects were then fed a test meal containing 50 g of purified bovine serum albumin which served as the model dietary protein. Electrophoretic analysis of intestinal fluids showed that for at least 4 h the fed albumin was detectable in jejunal and ileal fluids. On separate ...

Quantities of free amino acids in segments of cotton roots resistant and susceptible to Meloidogyne incognita were compared. Following infection, the root-knot susceptible cultivar, M8, had greater percentage increases of certain individual free amino acids than the resistant cultivar, Clevewilt, but the sum total of free amino acids was greatest in the resistant cultivar. More free amino acids...

Background: Given the important role of amino acids in regulating many metabolic pathways of the body and considering the scarcity of markers for the diagnosis of inflammatory bowel disease (IBD) and its differentiation, we aimed to investigate the status of serum amino acids chromatography in children with IBD. Materials and Methods This case-control study was conducted among children with pri...

The 15N-enrichments (atom percentage excess) were determined in the plasma free amino acids of blood samples taken at the time of feeding and in samples taken hourly and pooled over 12 h, as well as in ileal digesta, crude mucin, and bacteria collected at the distal ileum of pigs fed barley while continuously administered [15N]leucine intravenously. The branched-chain amino acids were the only ...

While free amino acids are routinely used in feeds for terrestrial farm animals, it is – except for few aqua species – not commonly practiced in finfish and shrimp nutrition. Reasons for not using free amino acids are often related to doubts on the efficiency and availability of these ingredients. This paper discusses aspects on the availability and efficiency of supplemental amino acids in fis...

Thermodynamics of the permeation of amino acids from water to lipid bilayers is an important first step for understanding the mechanism of cell-permeating peptides and the thermodynamics of membrane protein structure and stability. In this work, we employed bias-exchange metadynamics simulations to simulate the membrane permeation of all 20 amino acids from water to the center of a dipalmitoylp...

It has been known for many years that free amino acids are present in the blood and that their concentration increases after ingestion of a meal. In 1912 Van Slyke and Meyer (1) reported the presence of amino nitrogen in the non-protein fraction of the blood of dogs and that its concentra,tion increased after feeding meat. Abel et al. (2), using a vivi-diffusion apparatus, observed that free am...

On the assumption that all amino acids entering protein must pass through the intracellular pool of free amino acids, reutilization of leucine, lysine, arginine, and alanine was determined by pulse labeling of HeLa cell protein, followed by a chase in unlabeled medium and measurement of the specific activities of the intracellular free pool and protein amino acids. The half-lives of the amino a...