Urine relative density (weight) (in morning portion)

Urine relative weight in a healthy person depends on many factors but mainly on daily diuresis – the more is diuresis the lower is urine relative density which is measured with urometer.

In healthy people sum of 2 first ziphras in 24-houred diuresis and 2 latest ziphras in urine relative weight is 30. For instance, at 24-houred diuresis equal to 1100 ml, relative weight is 1019 g/l, than 11+19=30.

Isosthenuria – urine releasing with constant density level, protein-free blood plasma part density equal indexes (primary urine relative weight is 1010…1011g/l) testify to kidney concentrational function complete loss.

Hypersthenuria – urine relative weight is more than 1025 g/l:

1. Oedemas increasing:

   • acute glomerulonephritis;

   • circulation insufficiency.

2. Significant extrarenal liquid losses:

• diarrhea;

• vomiting;

• bleeding;

• spread burnings;

• oedemas formation;

• abdomen traumas;

• intestinal obturation (impermeability).

3. Appearance in urine big quantity of glucose, protein, medicines and their metabolites (3,3% of protein in urine increases its relative weight on 0,001).

4. Taking:

• mannitole;

• dextran;

• drugs used at X-ray examination.

5. Toxicosis of the pregnant.

Hyposthenuria – urine relative weight decreasing less than 1015 g/l main reasons:

• renal channels acute injure;

• diabetes unmellitus;

• chronic renal insufficiency;

• malignant hypertension.

Pathophysioogists tell about 3 main polyurias types:

1) Water diuresis – is determined by water facultative (non-obligatory) reabsorbtion decreasing. It appears at watery load, diabetes unmellitus. Urine is hypotonic because it ontains little amoun of osmotically-ative substances.

2) Osmotic diuresis (saluresis) is connected with increasing of non-reabsorbed asmotically-active substances in urine which leads to water reabsorbtion secondary disorder; reasons: electrolytes reabsorbtion disorders; threshold substances (glucose at diabetes mellitus) increasing in urine; exogenic substances action with weak reabsorbtion (mannitol) or the ones which disturb electrolytes reabsorbtion (saluretics); uroreleasing can reach 40% of glomerular filtration level under maximal diuresis conditions.

3. Hypertensive diuresis – is developed at arterial hypertension when blood velocity is increased in kidney medulla vasa recti (straight vessels) (these vessels come in parallel to Genle loop genuses). Na, Cl, urea are gone away from intersticium by active transport which leads to extracellular liquid hypoosmy and in turn to water reabsorbtion weakening in Genle loop descendent genus and polyuria.

83. Urine pathological components. Protein

Normal value: absent or traces (0,025-0,1 g/day).

Proteinuria is often non-specific symptom of kidney pathology. According to its value, one can tell about non-massive (proteins loss up to 3 g/day) and massive (more than 3 g/day) proteinuria. At renal proteinuria proteins can be detected both in morning and evening urine. Proteinuria is often combinated with cylindruria, erythrocyteuria, leucocyteuria.

Benz-Jons´ protein – low-molecular protein which is detected in urine at malignant new-formations in course of B-cells dysfunctions (myelomic disease).

Myoglobinuria – myoglobine appearance in urine – occurs at its level in plasma more than 0,15 g/l. Myoglobinuria can be primary and secondary. Primary one is hereditary determined in the biggest cases. It occurs due to muscular necroses and irreversible kidney changings combination. Such conditions are known as myorenal syndrom.

• hereditary muscles pathology;

• hard physical loadings (paroxysmal paralytic myoglobinuria);

• without hard physical loadings (idiopathic myoglobinuria);

• muscles necroses;

• muscles traumas;

• their long-termed ischemia;

• poisoning substances action.

Urine is dark brown at myoglobinuria.

Haemoglobinuria – free haemoglobine appearance in urine as the result of its content increasing in blood plasma up to 1,2 g/l. Reason – erythrocytes haemolysis.

Mostly often proteins loss with urine occurs due to albumines. Alpha-globulins can appear in urine at nephroses. Beta- and gamma-globulins are excreted with urine at primary amyloidosis and myelomic disease; alpha-2-macroglobulins and beta-lipoproteids - at proliferative and membranous glomerulonephritis.