Urate metabolism, renal urate handling and hyperuricaemia
Why humans run high urate levels, how purines become urate, how the proximal tubule reabsorbs 90% of filtered urate through URAT1 and GLUT9, how to calculate a fractional excretion of urate, which drugs raise or lower urate and why, and how rasburicase, allopurinol and urine pH fit the mechanism.
Tier 1Medical sciences concept
Written with AI assistance and fact-checked against the sources below. For exam study, not clinical decisions. How notes are made
At a glance
- Urate is the end product of purine catabolism in humans because we lack uricase. Normal serum urate runs up to about 0.42 mmol/L in men and 0.36 mmol/L in premenopausal women.
- Monosodium urate saturates at about 0.40 mmol/L (6.8 mg/dL) at 37 °C. Above that, crystals can form, but most people with hyperuricaemia never get gout.
- About two-thirds of daily urate leaves through the kidney and one-third through the gut (ABCG2). About 90% of hyperuricaemia is renal underexcretion.
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Sources
- Kelley and Firestein's Textbook of Rheumatology (11th ed.)Elsevier (Firestein, Budd, Gabriel, Koretzky, McInnes, O'Dell, 2021), 2021
- FitzGerald JD et al. 2020 American College of Rheumatology Guideline for the Management of Gout. Arthritis Care Res 2020;72:744-60American College of Rheumatology, 2020 (still the current ACR guideline, checked November 2026)
- Therapeutic Guidelines: Rheumatology (gout)AU/NZTherapeutic Guidelines Ltd, accessed November 2026
- Dalbeth N, Gosling AL, Gaffo A, Abhishek A. Gout. Lancet 2021;397:1843-55The Lancet, 2021
- Mandal AK, Mount DB. The molecular physiology of uric acid homeostasis. Annu Rev Physiol 2015;77:323-45Annual Review of Physiology, 2015
- EAU Guidelines on Urolithiasis (oral chemolysis of uric acid stones)European Association of Urology, accessed November 2026
- Last updated
- 14 November 2026
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