AJP - Endocrinology and Metabolism, Vol 241, Issue 6 415-E419, Copyright © 1981 by American Physiological Society
Amino acid release from the hindquarter and urea appearance in acute uremia
W. E. Mitch
Hepatic urea production is increased in acutely uremic rats, but it is not
known whether this is related to release of nitrogen from nonhepatic
tissues. Rats with acute uremia had lower arterial concentrations of
alanine, glutamine, and alpha-amino nitrogen when compared to sham-operated
rats and released significantly more alpha-amino nitrogen from the
hindquarter in situ. Release of alpha-amino nitrogen, alanine, and
glutamine from the perfused hindquarter of acutely uremic rats was greater
than that of sham-operated rats. These changes in situ and in the perfused
hindquarter were more pronounced in rats deprived of food and water
compared to fed animals and were not due to depletion of intracellular
amino acids. In addition to increased amino acid nitrogen release, there
was a higher urea appearance rate (excretion plus accumulation) in starved,
uremic rats compared to sham-operated controls (244.7 +/- 11.2 vs. 182.0
+/- 12.4 mg. 100 g-1 .48 h-1); urea appearance also was suppressed
partially by feeding. Both peripheral release of amino acids and diet
influence waste nitrogen production in acute uremia.
