NPN

Non-protein nitrogen compounds (NPNs)

Low molecular weight compounds containing nitrogen.

Where are NPNs primarily found in the body?

In urine.

Primary metabolic by-product of protein metabolism

Urea.

NPN with the highest plasma concentration

Urea.

Indicates renal function related to blood urea nitrogen (BUN)

Decreased renal perfusion.

Normal BUN range in mg/dL

6-20.

Method used to measure urea levels

High-Performance Liquid Chromatography.

Main end product of purine metabolism

Uric Acid.

Condition characterized by increased NPN in the blood

Azotemia.

Cause of pre-renal azotemia

Dehydration.

Elevated creatinine level indicates

Renal dysfunction.

Condition urea accumulates due to kidney failure

Uremia.

Primary source of ammonia in the body

Protein metabolism.

NPN synthesized in the liver from ammonia and carbon dioxide

Urea.

Factor that can falsely elevate urea measurement

High protein intake.

Normal creatinine range for adult males in mg/dL

0.6-1.2.

Main function of kidneys concerning NPNs

Excrete waste products.

Condition characterized by high uric acid levels

Gout.

Dietary factor that can increase urea production

High protein intake.

NPN known to be a marker for renal function

Creatinine.

Reference range for serum uric acid in adult males

4.0-8.5 mg/dL.

Major cause of hyperuricemia

Renal failure.

Common analytical method for measuring uric acid

Colorimetric assay.

Contributes to false decreases in creatinine measurement

Bilirubin.

Enzyme involved in converting creatine to creatinine

Creatinase.

Conversion factor for mg/dL to mmol/L for creatinine

0.357.

Condition associated with low urea levels

Liver disease.

Primary function of the urea cycle

Convert ammonia to urea.

Primary method used to measure ammonia levels

Enzymatic method.

Significant clinical consequence of elevated ammonia levels

Encephalopathy.