Non Protein

39問 • 2年前

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They are Nitrogen containing compounds that are not proteins or polypeptides

Non-Protein Nitrogen(NPN) Compounds

The determination of nonprotein nitrogenous substances in the blood has traditionally been used to monitor renal function.

Non-Protein Nitrogen(NPN) Compounds

What are the 4 Non-Protein Nitrogen(NPN) Compounds of interest?

Blood Urea Nitrogen Uric Acid Creatinine Ammonia

-It has the highest concentration of NPN in blood. -It is the major excretory product of protein metabolism

Blood Urea Nitrogen

Organisms synthesize urea from ___________ (a common metabolic waste product) because it raises pH in cells to toxic levels.

Ammonia

It is neither acidic nor basic, so it is a perfect vehicle for getting rid of nitrogen waste

Urea

Elevated concentration of nitrogenous waste in blood

Azotemia

Very high plasma urea concentration accompanied by renal failure

Uremia or Uremic syndrome

Causes of urea plasma elevations are classified into:

Pre-Renal Azotemia Renal Azotemia Post-Renal Azotemia

-Reduced renal blood flow -Less blood is delivered to the kidney -Less urea filtered -Anything that produces a decrease in functional blood volume. -High protein diet or increased catabolism

Pre-Renal Azotemia

Includes Congestive heart failure, shock, hemorrhage and dehydration

Pre-Renal Azotemia

Decreased renal function causes increased blood urea due to poor excretion

Renal Azotemia

Includes Acute & Chronic renal failure, Glomerular Nephritis and Tubular necrosis

Renal Azotemia

Obstruction of urine flow

Post-Renal Azotemia

Includes Renal calculi, Tumors of bladder or prostate and Severe infections

Post-Renal Azotemia

Decreased Urea Nitrogen are due to:

Low protein dietary intake Liver disease Severe vomiting and/or diarrhea (loss)Increase protein synthesis

Reference value of Urea Nitrogen Concentration

8 – 23 mg/dL ( 2.9 – 8.2 mmol/L)

Uses Diacetyl monoxime and strong acid to produce yellow diazine derivative

Fearson reaction

Ammonium is converted to indophenol with the addition of nitroprusside.

Berthelot reaction

Urea is first hydrolyzed to yield ammonium and bicarbonate ions by enzyme urease

Indirect method

-It is produced as a waste product of muscle metabolism -derived from creatine and creatine phosphate.

Creatinine

It is released into circulation at stable rate proportional to muscle mass. Filtered by glomerulus and excreted in urine.

Creatinine

It is synthesized in Liver from arginine, glycine & Methionine. Converted to Creatine Phosphate = high energy source for muscle tissue.

Creatine

Creatine is synthesized in Liver from arginine, glycine &methionine and converted to _____________ = high energy source for muscle tissue

Creatine Phosphate

It is the volume of plasma filtered (V) by the glomerulus per unit of time and used to estimate renal function.

GFR

A measure of the amount of creatinine eliminated from the blood by the kidneys per unit time.

Creatinine Clearance

Plasma concentration of creatinine is inversely proportional to Clearance. Therefore increased plasma levels mean _____________.

Decreased GFR

Isotope Dilution Mass Spectrometry

Reference method

It requires automated equipment for precision

Kinetic Jaffe Reaction

-Most frequently used, was first described in 1886 -Creatinine reacts with picric acid in alkaline solution → red-orange chromogen

Kinetic Jaffe Reaction (non specific)

It is a final breakdown product of purine metabolism(adenosine/guanine) in liver. Most other mammals degrade it further to Allantoin.

Uric acid

Uric acid is a final breakdown product of purine metabolism(adenosine/guanine) in liver. Most other mammals degrade it further to ___________.

Allantoin

READ! Uric acid is measured to: -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 nephropathy during chemotherapeutic Treatment -To detect kidney dysfunction

It is a disorder in which the proximal tubular function of the kidney is impaired,resulting in decreased reabsorption of electrolytes and nutrients back into the bloodstream

Fanconi Syndrome

(inborn error of purine metabolism) deficiency of hypoxanthine-guanine phosphoribosyl transferase.

Lesch – Nyhan syndrome

Primary method uses enzyme ____________ to convert uric acid to allantoin

Uricase (urate oxidase)

It comes from deamination of amino acids

Ammonia

Consumed by parenchymal cells of liver and converted to urea

Ammonia

Most common cause of abnormal ammonia levels

Severe liver disease

Translation(Pre-finals)

MAHATHIR ALPHA · 55問 · 2年前

Translation(Pre-finals)