[The mechanisms of urate transport in the kidney and the intestine].
Most urate is secreted from the kidney, but the intestine can also secrete urate. In the kidney, urate is transported in the proximal tubule which shows marked species differences. In human and rat, net urate reabsorption is seen, whereas rabbit and pig show net secretion. The transport of urate in the proximal tubule is bidirectional, reabsorption in S1, secretion in S2, and postsecretory reabsorption in S3. Although the mechanisms of transcellular urate transport are not fully understood, the influx of urate into the proximal tubule cell should be carried out by urate/anion exchanger, and the efflux by potential driven pathway. In the intestine, purine compounds are strongly metabolized to urate, that is transported. When the kidney function is normal, urate is reabsorbed, but in renal insufficiency urate can be excreted from the intestine.
Sekine
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T
Department of Pharmacology and Toxicology, Kyorin University School of Medicine.
Endou
H
H
D000368:Aged; D000818:Animals; D027321:Anion Transport Proteins; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism*; D011687:Purines / Q000378:metabolism; D011817:Rabbits; D051381:Rats; D013552:Swine; D014527:Uric Acid / Q000378:metabolism*
D027321:Anion Transport Proteins; D002352:Carrier Proteins; D011687:Purines; D014527:Uric Acid; C030985:purine