AJP - Renal Physiology, Vol 234, Issue 5 466-F451, Copyright © 1978 by American Physiological Society
Quantitation of renal uric acid synthesis in the chicken
T. Y. Chin and A. J. Quebbemann
The contribution of uric acid synthesized in the kidney (nephrogenic uric
acid) to the total uric acid excreted in the urine was studied in the
chicken by use of the isotope-dilution technique. In the non-fasted chicken
the urine-to-plasma specific activity ratio (SAR) of [14C]uric acid was
0.83, suggesting that a minimum of 17% of the uric acid excreted in the
urine is synthesized in the kidney. During allopurinol infusion into the
renal portal circulation of one kidney the SAR increased to 0.99,
indicating that the renal synthesis of uric acid was almost completely
inhibited and that the SAR is a valid indicator of the contribution of
nephrogenic uric acid excreted into the urine without first entering the
circulation. Chickens fasted for 18 h showed a lower rate of renal
synthesis of uric acid. Hypoxanthine infusion into the systemic circulation
increased the rate of renal synthesis of uric acid in both fasted and
nonfasted chickens, suggesting that circulating precursor levels may in
part regulate the renal synthesis of uric acid.
