Oe. Rooyackers et al., DERANGEMENT IN AEROBIC AND ANAEROBIC ENERGY-METABOLISM IN SKELETAL-MUSCLE OF CRITICALLY ILL AND RECOVERING RATS, Biochimica et biophysica acta. Molecular basis of disease, 1315(1), 1996, pp. 55-60
As part of our research into the mechanisms of protein wasting and mus
cle weakness during critical illness, we here investigate various aspe
cts of energy metabolism. Intraperitoneal injection of zymosan in rats
leads to an acute phase of critical illness followed by a prolonged r
ecovery phase. Previously we observed low activities of mitochondrial
enzymes, reduced protein synthesis rates and low concentrations of glu
tamine in skeletal muscle of zymosan-treated rats, In the present stud
y we investigated (1) whether decreases in high energy phosphates are
present in skeletal muscle of these rats and (2) whether an impairment
in the glycolytic pathway or the tricarboxylic acid cycle leads to th
ese decreases, Concentrations of creatine phosphate and ATP were decre
ased in zymosan-treated rats to approx. 85% of pair-fed control values
respectively on day 2 and on days 4 and 6 after treatment, Concentrat
ions of tricarboxylic acid (TCA) cycle intermediates were decreased to
80% on day 6 after zymosan treatment. Lactate/pyruvate ratio and conc
entrations of lactate and glycogen were normal at all sampling times,
We conclude that no major changes in concentrations of high energy pho
sphates and in concentrations of intermediates of TCA cycle, glycolysi
s and glycogenolysis were present. This indicated that, although the m
aximal oxidative capacity (mitochondrial content) is decreased, no der
angement in energy metabolism seems to be present in skeletal muscle o
f critically ill and recovering rats.