Glutamine deficiency in extracellular fluid exerts adverse effects on protein and amino acid metabolism in skeletal muscle of healthy, laparotomized, and septic rats
Abstract
In the present study we investigated the effects of GLN depletion in extracellular fluid on GLN production and protein and amino acid metabolism in skeletal muscle of healthy, laparotomized, and septic rats. Cecal ligation and puncture (CLP) was used as a model of sepsis.
After 24 hours, soleus muscle (SOL, slow-twitch, red muscle) and extensor digitorum longus (EDL, fast-twitch, white muscle) were isolated and incubated in a medium containing 0.5 mM GLN or without GLN. L-[1-14C]leucine was used to estimate protein synthesis and leucine oxidation, 3-methylhistidine release was used to evaluate myofibrillar protein breakdown.
It is concluded that (1) fast-twitch fibers are more sensitive to septic stimuli than slow-twitch fibers, (2) extracellular GLN deficiency may exert adverse effects on protein and amino acid metabolism in skeletal muscle, and (3) muscles of healthy and laparotomized animals are more sensitive to GLN deficiency than muscles of septic animals