DISORDERS OF URIC ACID METABOLISM Flashcards by Iseoluwa Ojo

PURINE DEGRADATION REVIEW
The end product of purine metabolism in humans is _______

uric acid.

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PURINE DEGRADATION REVIEW

The nucleotide monophosphates (_____,_____,_____ ) are converted to their respective ______ forms (_____,________,______ ) by the action of __________.

AMP, IMP & GMP

nucleoside

adenosine, inosine & guanosine

nucleotidase

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PURINE DEGRADATION REVIEW

The _____ group, either from AMP or adenosine, can be removed to produce _______ or _________.

amino

IMP or ionosine

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PURINE DEGRADATION REVIEW

Inosine & guanosine are converted to _______ and ———- (______ bases) by purine ___________ —————.

________ is not degraded by this enzyme, it has to be converted to ______.

hypoxanthine & guanine

purine

nucleoside phosphorylase

Adenosine; inosine

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PURINE DEGRADATION REVIEW

Guanine undergoes deamination by ______ to form ________.

____________ converts hyr.

guanase

xanthine

Xanthine oxidase

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Uric acid metabolism

Normal blood level of uric acid

Females: ___-___ mg/dl.
Males: ___-____ mg/dl.

The daily excretion varies from ____-____ mg.

2 -5

3 -7

500 – 700

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Nucleic acid content is (more or less?) in
non – vegetarian diet.

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Uric acid is very soluble in water.

T/F

Uric acid is sparingly soluble in water.

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HYPERURICEMIA

Hyperuricemia refers to an elevation in the ________ concentration.

This is sometimes associated with increased ___________ (_____uria)

serum uric acid

uric acid excretion

uricos

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Purine Catabolism

Purine bases are converted first into ______ and then into _____ for excretion.

______________ catalyzes two steps in this process.

xanthine

urate

Xanthine oxidase

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GOUT & PATHOPHYSIOLOGY

It is a metabolic disease associated with _____________ of _______

overproduction of uric acid.

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GOUT & PATHOPHYSIOLOGY

At the physiological pH, uric acid is found in a __________ form as ___________.

more soluble; sodium urate.

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GOUT & PATHOPHYSIOLOGY

In severe hyperuricemia, ______ of _______ get deposited in the ________ ,particularly in the _______.

Such deposits are commonly known as ______.

crystals of sodium urate

soft tissues; joints

tophi

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GOUT & PATHOPHYSIOLOGY

Deposit of Tophi
This causes ______ in the joints resulting in a (painful or painless?) __________.

inflammation

Painful; gouty arthritis

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GOUT & PATHOPHYSIOLOGY

Sodium urate or uric acid may also precipitate in ________ and ________ that results in ________ and _______ formation.

kidneys & ureters

renal damage & stone

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Gout is of two types.

List

Primary Secondary

GOUT & ITS PATHOPHYSIOLOGY

Primary
Increased _____________

Mostly affecting the (males or females?)

production of uric acid

Males

GOUT & ITS PATHOPHYSIOLOGY

Primary

CAUSES:

Increase in substrate levels of _______

Increased ___________,

PP-ribose-P

nucleic acid turnover

GOUT & ITS PATHOPHYSIOLOGY
Primary

CAUSES:

Specific ——— ______ defects

_________

Deficiency of enzymes of ________

heritable enzyme

PRPP synthetase

salvage pathway.

GOUT & ITS PATHOPHYSIOLOGY
Primary

CAUSES:
Increase in substrate levels of PP-ribose-P, e.g. _______,________

Increased nucleic acid turnover, e.g. ——— (especially during _____), infection, __________ anaemias, psoriasis.

obesity, idiopathic.

tumors; treatment

chronic haemolytic

GOUT & ITS PATHOPHYSIOLOGY
Primary

CAUSES:

Specific heritable enzyme defects, e.g. ______ or ______ deficiency, _______________ overactivity.

Deficiency of _______ of _______

HGPRT or G6PD

PP- ribose P synthetase

enzymes of salvage pathway.

GOUT & ITS PATHOPHYSIOLOGY

SECONDARY; Is due to various diseases causing ____________ or _________

increased synthesis or decreased excretion of uric acid.

GOUT & ITS PATHOPHYSIOLOGY

SECONDARY : CAUSES

_____________ defect (the cause in the commonest form of primary gout)

Decrease in ___________

______ or _______ affecting _________

Specific renal tubular

renal functional mass

Drugs or metabolites

tubular secretion

GOUT & ITS PATHOPHYSIOLOGY

SECONDARY: CAUSES.

Decrease in renal functional mass, e.g. ___________ or _____________

Drugs or metabolites affecting tubular secretion, e.g. ———,________,________ (in low dosage), _______ ,_________

acute or chronic renal failure

thiazides, ethanol, salicylates

lactate, β-hydroxy- butyrate

RISK FACTORS (Men or Women?) get gout more than (Men or Women?) by about _____ to ______.

Men; women three to one.

How is gout diagnosed? Diagnosis of gout usually involves: A ___________ of the ______ ________ of _________ _______ of ________ of an affected joint to ___________ of uric acid.

physical exam of the joints X-rays of affected joints Extraction of synovial fluid look for crystals

Risk factors Having one or more of the following conditions puts someone at a higher risk for gout. _______ dysfunction _______ disease Obesity High _______ High _________ ____________

Kidney Heart cholesterol triglycerides Diabetes

A definitive diagnosis of gout requires that ____ of the following 12 markers must be present: A ______ An episode of _______ in a ______ A history of ________________________ ________ of the skin around a joint _________ or _________ ——joint ________ of the ________ joint on _____ only _____ of ______ joints on _____ only

6 tophus arthritis in a single joint more than one such episode of arthritis Redness Swollen or painful big toe Inflammation; big toe ; one foot Inflammation; one or more midfoot; one foot

A tophus (________ deposits in the joints or body) Redness of the skin around a joint ( _____) Swollen or painful big toe joint (the _______ or _______ joint)

urate crystal erythema metatarsophalangeal or MTP

A definitive diagnosis of gout requires that ____ of the following 12 markers must be present: (Slow or Rapid?) joint _____ that reaches a maximum level within a _____ period _______ levels of uric acid in the blood An X-ray showing __________ in a joint An X-ray showing ________ or ________ without any indication of prior inflammation Joint _______ where the joint fluid tests _______ for infection.

6 Rapid; swelling; 24-hour Elevated uneven (asymmetric) swelling joint cysts or bone erosions inflammation; negative

TREATMENT OF GOUT The drug ______ is used for primary gout It is a _______ of _______ that _______vely inhibits enzyme _______ Changes in diet to avoid foods ___________ reduce the inflammation and pain in _____ cases. Your doctor may also prescribe ______ (to alleviate pain and swelling).

Allopurinol structural analog of hypoxanthine competiti; xanthine oxidase high in purines ; mild; NSAIDs

TREATMENT OF GOUT For more severe gout, other medications are needed to lower the uric acid. These may include one or more of the following: _______ (Uloric) _________ (Colcrys) _________ (Zurampic) __________ (Zyloprim) ______________(Krystexxa)

Mnemonic: Fucking CLAP! Febuxostat Colchicine Lesinurad Allopurinol Pegloticase

OTHER URIC ACID METABOLISM DISORDERS Lesch-Nyhan syndrome It is due to the deficiency of ___________________ an enzyme of ________ It is a/an (autosomal or sex linked?) metabolic disorder affects ______

hypoxanthine guanine phosphoribosyl transferase (HGPRT) purine salvage pathway. sex linked; only male

OTHER URIC ACID METABOLISM DISORDERS Lesch-Nyhan syndrome _______, _______ behaviour, _____ disability etc Irresistible urge to __________, often causing _______

Mental retardation aggressive ; learning bite their fingers and lips self mutilation.

OTHER URIC ACID METABOLISM DISORDERS XANTHINURIA ____eased uric acid levels in the serum (___mg/dl) called as hyperuricemia Mostly associated with a rare genetic defect in the enzyme ______ Leads to the _____eased excretion of ________ and _______

Decr Less than 2 xanthine oxidase; incr xanthine and hypoxanthine

OTHER URIC ACID METABOLISM DISORDERS XANTHINURIA Xanthinuria frequently causes the formation of ________ in the ________

xanthine stones urinary tract.