Urea in the blood. Increased and decreased content

Urea is synthesized in the process of neutralizationammonia in the liver. It forms in the reactions of amino acid deamination. Urea refers to compounds of low molecular weight. It has the ability to freely pass through the cellular membranes of erythrocytes and parenchymatous organs. Urea filtration is from the blood in the glomeruli. But at the same time, its significant reabsorption (passive) occurs in the tubules.

Urea in the blood is concentrated depending on the speed of the synthesis of glomerular filtration and renal perfusion.

This compound is low toxicity, however, toxicityThe derivatives of guanidine and potassium ions accumulate together with it. Urea is also a substance that is osmotically active, so when it accumulates, swelling of the tissues in the parenchymal organs, myocardium, central nervous system, and subcutaneous tissue is noted.

Urea in the blood (its concentration in the plasma) is often considered an indicator of the function of the glomerular renal apparatus. However, a more accurate assessment is carried out on the content of creatinine.

Increasing urea formation is noted whenthe use of excessive amounts of protein, catabolic states, as well as the absorption of proteins and amino acids after gastric bleeding. An increase in its concentration is observed during dehydration as a result of increased passive reabsorption in the tubule of the kidneys.

Reduced urea in the blood (in plasma) atthe disorder of the synthetic hepatic function, as well as with insufficient intake of proteins. The content of the compound in the serum can increase due to the intake of individual drugs. Such medicines include butadione, anabolic steroids, dopegit, iron preparations, aldomet, nephrotoxic drugs.

Decreased urea in the blood can indicateliver disease (hepatitis, including viral, cirrhosis, tumors). This is due to the fact that the basic formation of this compound occurs in this organ. If there is a violation of the liver, a breakdown in the production of urea occurs. However, the symptoms of the disease can not always be clearly expressed. The main manifestations should be considered weakness, decreased appetite, increased fatigue, jaundice, bitter eructations, discomfort in the right hypochondrium.

With diseases of the digestive system, whichare accompanied by a violation of absorption of amino acid constituents, post-operative periods associated with interventions for intestinal ailments, chronic pancreatitis, parasitic diseases, and decreased urea in the blood. Treatment in this case should be aimed at eliminating the underlying disease. As a rule, after getting rid of the disease, analyzes are normalized.

It should be noted that the content of the compound in the urine is determined by its concentration in the blood. The amount of filtration in the kidneys is also taken into account.

The norm of urea in the blood is 2.8-8.3 mmol / l. As a rule, with a normal process of protein metabolism, its content is rarely noted above 6 mmol / l. In case there is a diet with a low protein content, the concentration of the compound is reduced to 2 mmol / l.

Increased urea in the blood (usually concentrationseveral times higher than the normal upper indices), accompanied by a usually pronounced intoxication, is called uremia. This condition is noted against the background of the following diseases:

- acute renal failure;

- pyelonephritis, glomerulonephritis;

- Anuria (a syndrome of absence of urine, a person does not defecate);

- diabetes;

- tumors or concrements in the urethra or ureters;

- burns;

- peritonitis;

- shock;

poisoning with phenol, mercury salts, chloroform;

- gastrointestinal bleeding.

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