Contents

Search

urea (carbamide)

Function: - waste product of nitrogen catabolism, i.e. catabolism of proteins, nucleic acids etc - formed in the liver from NH3 via the urea cycle; NH3 is a degradation product of nitrogen-containing compounds - urea formed in the liver is excreted into the kidney - in the kidney, urea plays a role in the countercurrent exchange system of nephrons, allowing reabsorption of water & ions from urine - urea is reabsorbed in the inner medullary collecting ducts of the nephrons, thus raising osmolarity in the renal medullary interstitium surrounding the thin ascending limb of the loop of Henle, which in turn causes water to be reabsorbed - the urea transporter 2 allows some reabsorbed urea to flow back into the thin ascending limb of the tubule, through the collecting ducts, & into the excreted urine - the countercurrent exchange system is controlled by vasopressin which allows the body to create hyperosmotic urine, with a higher concentration of dissolved substances than in blood plasma - this serves to prevent the loss of water, maintain blood pressure, & to maintain a normal Na+ in plasma Laboratory: - urea in body fluid - urea in amniotic fluid - urea in blood - urea in CSF - urea in dialysis fluid - urea in peritoneal dialysis fluid - urea in gastric fluid - urea in peritoneal fluid - urea in pleural fluid - urea in serum/plasma/blood - urea in serum/plasma - urea in stool - urea in urine - urea in vitreous fluid - urea nitrogen in body fluid - urea nitrogen in amniotic fluid - urea nitrogen in blood - urea nitrogen in CSF - urea nitrogen in dialysis fluid - urea nitrogen in peritoneal dialysis fluid - urea nitrogen in gastric fluid - urea nitrogen in peritoneal fluid - urea nitrogen in pleural fluid - urea nitrogen in serum/plasma - urea nitrogen in synovial fluid - urea nitrogen in urine - urea nitrogen in vitreous fluid Pharmacology: - urea is considered a medical food by the FDA [3] - urea 15 g BID mixed with fruit juice is used for treatment of euvolemic hyponatremia (SIADH) with low plasma osmolality & high urine osmolality not responding to fluid restriction [3]

Interactions

molecular events

Related

urea cycle urea in serum/plasma urea nitrogen in 24 hour urine uremia

Specific

5,6-dihydrouracil urea topical (Keratol)

General

bioagent small molecule

Properties

COMPARTMENT: plasma serum

Database Correlations

PUBCHEM cid=1176

References

  1. Wikipedia: Urea http://en.wikipedia.org/wiki/Urea
  2. Department of Veterans Affairs, VA National Formulary
  3. Rondon-Berrios H, Tandukar S, Mor MK et al Urea for the Treatment of Hyponatremia. Clin J Am Soc Nephrol. 2018 Nov 7;13(11):1627-1632. PMID: 30181129 PMCID: PMC6237061 Free PMC article.

Component-of

ammonium lactate/urea chlorophyllin/copper/papain/urea chlorophyllin/papain/urea chlorophyllin/urea cysteine/inositol/methionine/propionate/urea cysteine/inositol/methionine/urea hyaluronate/urea lactate/urea lactic acid/urea papain/urea (Panifil-White, Rystan, Kovea) salicylic acid/urea sulfacetamide/urea