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Effects of chronic acidosis onprotein metabolism
M. V. Kryshtal
A.A. Bogomoletz National Medical University, Kiev

Abstract
In experiments on mongrel albino male rats, we studied the
effects of 30 mmol/kg lactic acid, 30 mmol/kg NaHCO 3</subsub>, and
20 mmol/kg NH4Cl (intraventricular injections, daily for
7 days) on the contents of total protein, residual nitrogen,
urea, and creatinine in the blood, as well as on the activities of
aldolase and alanine aminotranspherase (ALT). We also studied
the effects of the above agents on renal functions: glomerular
filtration rate (GFR), diuresis, and excretion of ammonium,
creatinine, and protein with urine. We have found that
chronic, hyperchloremic, and lactic acidosis resulted both in a
significant decrease in the levels of protein and residual nitrogen
and in an increase in the concentration of the urea; these
phenomena were accompanied by a considerable intensification
of the urinary NH4+ excretion. In contrast, under conditions
of chronic alkalosis we observed a drop in the level of
urea in the blood with no changes in the concentrations of
protein and residual nitrogen, as well as a dramatic depression
of the urinary NH4+ excretion. In that case, the concentration
of creatinine in the blood, GFR, diuresis, and excretion
of creatinine and protein with urine did not correlate
with the above-mentioned changes in protein metabolism. In
all experiments, the activities of aldolase and ALT preserved
their normal level giving evidence against damage to the liver.
These results give evidence for spending a great number of
amino acids on the renal ammoniogenesis at chronical acidosis;
their saving at alkalosis; an impairment of the protein
synthesis, and an increase in protein catabolism at acidosis to
replenish the pool of amino acids, as well as for an activation
of the urea synthesis to eliminate the excessive amount of
NH4+ from the blood.
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