NON-PROTEIN NITROGENOUS COMPOUNDS 2 Flashcards
metabolic waste product of purine metabolism
URIC ACID
_______reabsorbed by PCT
98-100%
URIC ACID
small amount are secreted by _______
DCT (Distal convoluted tubule)
___________is formed from the breakdown of nucleic acids and in is an end product of purine metabolism
Uric acid
__________ is transported by the plasma from the liver to the kidney, where it is filtered and where about ______ is excreted
Uric acid - 70%
The remainder of uric acid is excreted into the _________
GI tract
At concentrations greater than _______ the plasma is saturated
relatively insoluble (blood pH)
6.8 mg/dl
Resulting to _____________
urate crystal formations
Why measure uric acid?
(5)
To assess inherited disorders of purine metabolism
To confirm diagnosis and monitor treatment of gout
To assist in the diagnosis of renal calculi
To prevent uric acid and nephropathy during chemotherapeutic treatment
To detect kidney dysfunction
(5)
In disease correlation there are three elevated Uric acid disease (3)
- Gout
- Increased catabolism of nucleic acids
- Renal diseases
GIR
-precipitation of sodium urates in the joints
cause hyperuricemia
prone to renal calculi
tophi formations (tissues)
- Gout
DISEASE CORRELATION
In patients with proliferative disorders on “chemotheraphy”
- monitoring Uric acid level to avoid nephrotoxicity
leukemia
lymphoma
multiple myeloma
polycythemia
treatment of proliferative disorders
TX: Allopurinol
DISEASE CORRELATION
other renal disease:
- hemolytic or megaloblastic anemia
- lesch nyhan syndrome
- glycogen storage disease
- G-6-PD deficiency
HLGG
Filtration and secretion are impaired
Chronic renal disease
- X linked genetic disorder
- Complete deficiency of hypoxanthine guanine phosphoribosyltransferase
Lesch-Nyhan Syndrome
Prevents reutilization of purine bases resulting to increased Uric acid
Lesch-Nyhan syndrome
- Toxemia of pregnancy and lactic acidosis
- Ingestion of purine-rich diet
- starvation
TIS
Hyperuricemia
hyperuricemia
ingestion of purine rich diet
liver, kidney, shellfish, legumes
LKSL
Secondary to liver disease
defective tubular reabsorption
hypouricemia
disorder of reabsorption in the PCT
Fanconi’s Syndrome
- 6-mercaptopurine or azathioprine
- overtreatment with allopurinol
Chemotheraphy
Based on the oxidation of UA in PFF with subsequent reduction of phospotungstic acid to tungsten blue
- Caraway Method
provides alkaline pH for color development
Sodium carbonate
small collection of sodium urate crystals
in the joint
Tophi
→ Has a MW of 168 Da
Filtered by the glomerulus
Exogenous
diet
Endogenous
liver, intestine and other
tissues
Guanine will be acted upon by _________________
guanine deaminase
→ Guanosine will be converted to Guanine via ______________
nucleosidase
Guanine will be acted upon by _________________
guanine deaminase
Earlier uric acid crystal formation due to the
abnormal levels of UA in the urine is demonstrated
by the orange colored deposits in the diapers
Lesch Nyhan syndrome
Urate stones can also develop and is demonstrated
by the blood in urine
Lesch Nyhan syndrome
Toxemia of pregnancy and lactic acidosis
▪ Ingestion of Purine-rich diet
− Liver, kidney, shellfish, legumes
▪ Starvation; tissue catabolism induced by inadequate
dietary intake
Hyperuricemia