AJP - Endocrinology and Metabolism, Vol 244, Issue 6 615-E623, Copyright © 1983 by American Physiological Society
Protein and amino acid metabolism in posterior hemicorpus of acutely uremic rats
R. M. Flugel-Link, I. B. Salusky, M. R. Jones and J. D. Kopple
Protein synthesis and degradation and net uptake and release of amino acids
and minerals were examined in the perfused hemicorpus of bilaterally
nephrectomized and sham-operated control rats. Animals were studied 30 h
after surgery. In comparison with controls, uremic rats had greater urea N
appearance (net urea generation) and lower plasma and muscle concentrations
of most amino acids. Muscle protein synthesis was not altered, but protein
degradation was greater in uremic versus sham rats. There was greater net
release of phenylalanine, tyrosine, alanine, total nonessential amino
acids, total amino acids, potassium, and phosphorus from the perfused
hemicorpus of uremic rats and greater release of citrulline from sham rats.
ATP, creatine phosphate, cAMP, and activities of cathepsin B1, cathepsin D,
and alkaline protease were not different in muscles of the uremic versus
sham rats. Thus, in acutely uremic rats there is increased protein wasting
in the hemicorpus due to enhanced protein degradation. The enhanced protein
degradation does not appear to be due to increased muscle cathepsin B1,
cathepsin D, or alkaline protease activities.
