uric acid production

8/14/2019 Uric Acid Production

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URIC ACID PRODUCTIONPRESENTED BY:NEHA SRIVASTAVABBT-2-08047


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INTRODUCTION

Uric acid (or urate) is aheterocyclic compound ofcarbon,nitrogen, oxygen, and hydrogenwith the formula C5H4N4O3
http://en.wikipedia.org/wiki/Heterocyclic_compoundhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Chemical_formulahttp://en.wikipedia.org/wiki/Hydrogenhttp://en.wikipedia.org/wiki/Oxygenhttp://en.wikipedia.org/wiki/Nitrogenhttp://en.wikipedia.org/wiki/Carbonhttp://en.wikipedia.org/wiki/Heterocyclic_compound


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PRODUCTION OF URIC ACID FROM

PURINES Purines are metabolized into uric

acid When cells die and get recycled, the

purines in their genetic materialalso get broken down. Uric acid isthe chemical formed when purines

have been broken down completely.It's normal and healthy for uric acidto be formed in the body frombreakdown of purines.


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Reaction:

Uric acid is produced by xanthine

oxidase from xanthine andhypoxanthine, which in turn areproduced from purine. Uric acid ismore toxic to tissues than eitherxanthine or hypoxanthine
http://en.wikipedia.org/wiki/Xanthine_oxidasehttp://en.wikipedia.org/wiki/Xanthine_oxidasehttp://en.wikipedia.org/wiki/Xanthinehttp://en.wikipedia.org/wiki/Hypoxanthinehttp://en.wikipedia.org/wiki/Purinehttp://en.wikipedia.org/wiki/Tissue_(biology)http://en.wikipedia.org/wiki/Xanthinehttp://en.wikipedia.org/wiki/Hypoxanthinehttp://en.wikipedia.org/wiki/Hypoxanthinehttp://en.wikipedia.org/wiki/Xanthinehttp://en.wikipedia.org/wiki/Tissue_(biology)http://en.wikipedia.org/wiki/Purinehttp://en.wikipedia.org/wiki/Hypoxanthinehttp://en.wikipedia.org/wiki/Xanthinehttp://en.wikipedia.org/wiki/Xanthine_oxidasehttp://en.wikipedia.org/wiki/Xanthine_oxidase


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ROLE OF URIC ACID IN HUMAN

uric acid serves as an antioxidantand helps prevent damage to ourblood vessel linings, so a

continual supply of uric acid isimportant for protecting ourblood vessels. .

In humans, over half the

antioxidant capacity ofblood lasma comes from uric
http://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Blood_plasma


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Research article about role of uric

acid Towards the physiological function of uric acid. Becker BF.

Department of Physiology, University of Munich, Germany. Uric acid, or more correctly (at physiological pH values), its

monoanion urate, is traditionally considered to be a metabolically inertend-product of purine metabolism in man, without any physiologicalvalue. However, this ubiquitous compound has proven to be aselective antioxidant, capable especially of reaction with hydroxylradicals and hypochlorous acid, itself being converted to innocuousproducts (allantoin, allantoate, glyoxylate, urea, oxalate). There is nowevidence for such processes not only in vitro and in isolated organs,but also in the human lung in vivo. Urate may also serve as anoxidisable cosubstrate for the enzyme cyclooxygenase. As shownfor the coronary system, a major site of production of urate is themicrovascular endothelium, and there is generally a net release ofurate from the human myocardium in vivo. In isolated organpreparations, urate protects against reperfusion damage inducedby activated granulocytes, cells known to produce a variety ofradicals and oxidants. Intriguingly, urate prevents oxidativeinactivation of endothelial enzymes (cyclooxygenase, angiotensinconverting enzyme) and preserves the ability of the endotheliumto mediate vascular dilatation in the face of oxidative stress,

suggesting a particular relationship between the site ofurateformation and the need for a biologically potent radical
http://www.ncbi.nlm.nih.gov/pubmed?term=%22Becker%20BF%22%5BAuthor%5Dhttp://www.ncbi.nlm.nih.gov/pubmed?term=%22Becker%20BF%22%5BAuthor%5D


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URICOTELISM

Uricotelism Elimination of uric acid as the main

nitrogenous waste material is calleduricotelism. Animals showinguricotelism are called uricotelicanimals.

Occurrence It is a common method seen in birds,

land reptiles, insects, land snails andsome land crustaceans.


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THE THREE MODES OF EXCRETION

OF NITROGENOUS COMPOND


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Uric acid excretion

In humans and higher primates, uric acid isthe final oxidation (breakdown) productofpurinemetabolism and is excreted in

urine. In birds and reptiles, and in some desert

dwelling mammals (e.g., thekangaroo rat), Uric acid is formed fromammonia mostly in the liver and to someextent in the kidneys apart from this

uric acid also is the end product of purinemetabolism, but it is excreted in feces as adry mass.
http://en.wikipedia.org/wiki/Humanshttp://en.wikipedia.org/wiki/Higher_primateshttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Purine_metabolismhttp://en.wikipedia.org/wiki/Purine_metabolismhttp://en.wikipedia.org/wiki/Urinehttp://en.wikipedia.org/wiki/Birdhttp://en.wikipedia.org/wiki/Reptilehttp://en.wikipedia.org/wiki/Kangaroo_rathttp://en.wikipedia.org/wiki/Feceshttp://en.wikipedia.org/wiki/Feceshttp://en.wikipedia.org/wiki/Kangaroo_rathttp://en.wikipedia.org/wiki/Reptilehttp://en.wikipedia.org/wiki/Birdhttp://en.wikipedia.org/wiki/Urinehttp://en.wikipedia.org/wiki/Purine_metabolismhttp://en.wikipedia.org/wiki/Purine_metabolismhttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Higher_primateshttp://en.wikipedia.org/wiki/Humans


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Uric acid from ammonia

Uric acid is formed from ammoniamostly in the liver and to some extentin the kidneys. The process is highly

energy dependant, but is much lesstoxic than both ammonia and ureaand it is almost insoluble in water andcan be eliminated from the body innearly a solid state, saving a lot ofwater.

In humans, about 70% of daily uric acid

disposal occurs via the kidneys


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Excretion of uric acid in human, Uric acid is produced as themajor end-product of purinemetabolism by muscles, liver andintestine. b, After the blood isfiltered at the glomerulus, theresulting fluid enters the tubulesof the kidneys to allow wastesubstances to be excreted asurine. Many substances, however,such as uric acid, are useful andso are reabsorbed. This isachieved by the cells that line thewalls of the tubules, as seen indetail at the right. As shown byEnomoto et al.1, the transporterURAT1 mediates uptake of uricacid across the apical membrane,in exchange for anions, whichenter cells either by Na+-coupledtransport through the apicalmembrane or organic aniontransport (through OAT proteins)across the basolateral membrane.Uric acid leaves the cell across the

basolateral membrane through anunknown channel or transporter,possibly in exchange for anionsthrough an OAT protein
http://www.nature.com/nature/journal/v417/n6887/full/417393a.htmlhttp://www.nature.com/nature/journal/v417/n6887/full/417393a.html


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URIC ACID RELATED

DISORDERS In human blood plasma, the reference range of

uric acid is between 3.6 mg/dL (~214mol/L)and 8.3 mg/dL (~494mol/L) (1 mg/dL=59.48mol/L). This range is considered normal by

the American Medical Association. Uric acidconcentrations in blood plasma above andbelow the normal range are known,respectively, as hyperuricemia andhypouricemia.

Similarly, uric acid concentrations in urine aboveand below normal are known ashyperuricosuria and hypouricosuria. Suchabnormal concentrations of uric acid are notmedical conditions, but are associated with avariety of medical conditions
http://en.wikipedia.org/wiki/Blood_plasmahttp://en.wikipedia.org/wiki/Reference_ranges_for_blood_testshttp://en.wikipedia.org/wiki/American_Medical_Associationhttp://en.wikipedia.org/wiki/Hyperuricemiahttp://en.wikipedia.org/wiki/Hypouricemiahttp://en.wikipedia.org/wiki/Urinehttp://en.wikipedia.org/wiki/Hyperuricosuriahttp://en.wikipedia.org/w/index.php?title=Hypouricosuria&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Hypouricosuria&action=edit&redlink=1http://en.wikipedia.org/wiki/Hyperuricosuriahttp://en.wikipedia.org/wiki/Urinehttp://en.wikipedia.org/wiki/Hypouricemiahttp://en.wikipedia.org/wiki/Hyperuricemiahttp://en.wikipedia.org/wiki/American_Medical_Associationhttp://en.wikipedia.org/wiki/Reference_ranges_for_blood_testshttp://en.wikipedia.org/wiki/Blood_plasma


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HIGH URIC ACID

Gout Excess serum accumulation of uric acid can lead to a type ofarthritis known as gout.Gout

Gout can be controlled by diet and/ora drug called allopurinol which

inhibits the enzyme which producesuric acid.
http://en.wikipedia.org/wiki/Arthritishttp://en.wikipedia.org/wiki/Arthritishttp://en.wikipedia.org/wiki/Gouthttp://en.wikipedia.org/wiki/Gouthttp://en.wikipedia.org/wiki/Gouthttp://en.wikipedia.org/wiki/Arthritis


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Lesch-Nyhan syndrome

Lesch-Nyhansyndrome,an extremely rare

inherited disorder, is alsoassociated with very highserum uric acid levels.
http://en.wikipedia.org/wiki/Lesch-Nyhan_syndromehttp://en.wikipedia.org/wiki/Lesch-Nyhan_syndromehttp://en.wikipedia.org/wiki/Lesch-Nyhan_syndromehttp://en.wikipedia.org/wiki/Lesch-Nyhan_syndrome


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URIC ACID STONE

5-25% of humans impaired renal(kidney) excretion leads to urickidney stone


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LOW URIC ACID

Multiple sclerosis Lower serum values of uric acid have

been associated withMultiple Sclerosis.
http://en.wikipedia.org/wiki/Multiple_Sclerosishttp://en.wikipedia.org/wiki/Multiple_Sclerosis


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Oxidative stress

Oxidative stress Uric acid may be a marker of

oxidative stress, and may have apotential therapeutic role as anantioxidant.
http://en.wikipedia.org/wiki/Oxidative_stresshttp://en.wikipedia.org/wiki/Antioxidanthttp://en.wikipedia.org/wiki/Antioxidanthttp://en.wikipedia.org/wiki/Oxidative_stress


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Oxidative stress

Antioxidant prooxidant urate redox shuttle. The antioxidant prooxidant urate redox shuttle is an important concept to understandregarding accelerated atherosclerosis. This shuttle is important inunderstanding the role of how the antioxidant uric acid becomes prooxidant inthis environmental milieu, which results in its damaging role to theendothelium and arterial vessel wall remodeling with an elevated tension ofoxidative redox stress (ROS), accelerated atherosclerosis and arterial vesselwall remodeling.


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Sources of uric acid

In humans Purines are excreted as uric acid. Purines arefound in high amounts in animal food products, such asliver and sardines

Moderate intake of purine-containing food is not associatedwith an increased risk of gout, A moderate amount ofpurine is also contained in beef, pork, poultry, fish andseafood, asparagus, cauliflower, spinach, mushrooms,green peas, lentils, dried peas, beans, oatmeal, wheatbran and wheat germ.

In many instances, people have elevated uric acid levels for

hereditary reasons. Diet may also be a factor; eatinglarge amounts of sea salt can cause increased levels ofuric acid.

Serum uric acid can be elevated due to reduced excretionby the kidneys, and or high intake of dietary purine.[


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uric acid production

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