cc leeccc Flashcards
The NPN fraction comprises
15 compounds
Majority of these compounds arise from catabolism of
proteins and nucleic acids
Highest concentration of NPN in blood
Urea Nitrogen
Major excretory product of protein metabolism
Urea Nitrogen
Urea releases _____, which is converted to
nitrogen, ammonia
urea is synthesized in the
liver
Concentration or BUN is determined by
- Renal function
- Dietary intake
- Protein catabolism rate
elevated conc. of urea in blood
Azotemia
Very high plasma urea concentration accompanied by
renal failure is called
uremia, or the uremic syndrome
Causes of urea plasma elevations are
- Prerenal
- Renal
- Postrenal
These drugs (eg Probenecid) increase the urinary excretion of urate by inhibiting tubular reabsorption
Uricosuric agents
These agents (eg colchicine and indomethacin) are used symptomatically to relieve the pain of acute gouty arthritis.
Anti-inflammatory agents
inhibit the enzyme xanthine oxidase, producing a decrease in the plasma and urinary concentrations of urate
Allopurinol
Some patients may have only 1 attack, whilst others have recurrent attacks at shorter intervals.
Intercritical Gout
This follows recurrent attacks and is characterised by the development of tophi (swellings containing uric acid crystals) in the periarticular tissue
Chronic Tophaceous Gout
is usually present for many years
before the onset of symptoms.
Asymptomatic Hyperuricaemia
Classical presentation is acute inflammation of the
metatarsophalangeal joint of the big toe (70%), and the first attack is usually monoarticular (affects
only 1 joint)
Acute Gouty Arthritis
is a group of metabolic diseases associated with hyperuricaemia
and deposition of crystals of monosodium urate in tissues.
Gout
is associated with a tendency to form crystals of monosodium urate
Hyperuricemia
is the end product of purine
metabolism.
Uric acid
Primarily in men
Gout
Occurs in patients on chemotherapy for diseases
such as leukemia & multiple myeloma
Increased catabolism
treatment of Increased catabolism
Allopurinol
causes elevated levels of uric acid because filtration and secretion are hindered
Chronic renal disease
Secondary to severe liver disease
Hypouricemia
proximal tubular function of the kidney is impaired
Fanconi’s Syndrome
treatment of hypourecemia
allopurinol
Reference range of UA
Males: 0.5-7.2 mg/dl
Females: 2.6-6.0 mg/dl
