Intracellular Free Amino Acids in Undernourished Patients with or without Sepsis

Abstract

1. Thigh muscle samples for analysis were obtained from 35 control subjects and 12 severely ill patients, of whom five had disease-induced undernutrition and seven had associated sepsis. An improvement in the Bergström technique for analysing muscle needle biopsy samples was used. 2. Muscle water, chloride and DNA were increased in both groups of ill patients, indicating an increase in the extracellular component and loss of muscle protein. 3. Falls in the concentrations of glutamine, glutamate, arginine, histidine, ornithine and lysine and rises in those of glycine, serine, asparagine, tyrosine, valine, leucine, isoleucine, phenylalanine, methionine and tryptophan were observed in the group of ill patients compared with those in the control subjects. The changes were present mainly in the patients with sepsis, significant differences between these and the undernourished ones without associated sepsis being observed in glutamine, lysine, tyrosine, valine, leucine, isoleucine, phenylalanine and methionine. The changes were either absent or slight in plasma. 4. The increased concentrations observed in six essential amino acids in the septic patients, but not in those with undernutrition, is consistent with the increased catabolic rate of sepsis. 5. However, the branched-chain amino acids, and lysine, threonine, arginine, and histidine, were present in lower concentrations than might be expected from catabolism, presumably due to utilization. It is suggested therefore that septic patients might benefit from increased proportions of these amino acids in their feeding regimen.

Nitric oxide and l-arginine metabolism in a devascularized porcine model of acute liver failure

“…This finding was described in the early description of this devascularized porcine model of acute liver failure, wherein they also found that the concentrations of citrulline and ornithine were increased (24). In septic patients, low arginine levels (16,25) have also been observed, which is associated with poor outcome. Arginine clearance was found to progressively increase over the duration of the study (Fig.…”

The Effects of Arginine and Selective Inducible Nitric Oxide Synthase Inhibitor on Pathophysiology of Sepsis in a CLP Model

“…Arginine, the precursor of NO, is a nonessential amino acid for healthy adults but is essential for wound healing, protein anabolism, and immunity after injury [11]. Many studies have indicated that arginine is deficient in sepsis, particularly in patients who died of septic shock [12], and cNOS starts to produce superoxide (O 2 Ϫ ) when arginine concentration is low [13]. Peroxynitrite (ONOO Ϫ ) generated by reaction of NO with O 2…”

Antimicrobial effects of arginine and nitrogen oxides and their potential role in sepsis

“…Some authors have proposed that sepsis might be an ARGdeficient state [73]. In both animals and humans with sepsis, plasma ARG concentrations were found to be significantly decreased [50,[74][75][76], suggesting that endogenous synthesis and supply from dietary intake are unable to keep up with the increased demand. In infection body protein breakdown is increased [74] to make more ARG available for nitric oxide synthesis.…”