PART 16: Endocrinology and Metabolism
SECTION 3 Disorders of Intermediary Metabolism
359 Disorders of Purine and Pyrimidine Metabolism
 | Figure 359-1 The total-body urate pool is the net result between urate production and excretion. Urate production is influenced by dietary intake of purines and the rates of de novo biosynthesis of purines from nonpurine precursors, nucleic acid turnover, and salvage by phosphoribosyltransferase activities. The formed urate is normally... |
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 | Figure 359-2 Schematic for handling of uric acid by the kidney. A complex interplay of transporters on both the apical and basolateral aspects of the renal tubule epithelial cell is involved in the reabsorption of uric acid. Please see text for details. Most uricosuric compounds inhibit URAT1 on the apical side, as well as OAT1, OAT3, and GLUT9 on the basolateral... |
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 | Figure 359-3 Abbreviated scheme of purine metabolism. (1) Phosphoribosylpyrophosphate (PRPP) synthetase, (2) amidophosphoribosyltransferase (amidoPRT), (3) adenylosuccinate lyase, (4) (myo-)adenylate (AMP) deaminase, (5) 5′-nucleotidase, (6) adenosine deaminase, (7) purine nucleoside phosphorylase, (8) hypoxanthine... |
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 | Figure 359-4 Abbreviated scheme of pyrimidine metabolism. (1) thymidine kinase, (2) dihydropyrimidine dehydrogenase, (3) thymidylate synthase, (4) UMP synthase, (5) 5′-nucleotidase. CMP, cytidine-5′-monophosphate; UMP, uridine-5′-monophosphate; UDP, uridine-5′-diphosphate; dUMP, deoxyuridine-5′-monophosphate;... |
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