Myoglobinuria
Encyclopedia
Myoglobinuria is the presence of myoglobin
Myoglobin
Myoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals. It is related to hemoglobin, which is the iron- and oxygen-binding protein in blood, specifically in the red blood cells. The only time myoglobin is found in the...

 in the urine
Urine
Urine is a typically sterile liquid by-product of the body that is secreted by the kidneys through a process called urination and excreted through the urethra. Cellular metabolism generates numerous by-products, many rich in nitrogen, that require elimination from the bloodstream...

, usually associated with rhabdomyolysis
Rhabdomyolysis
Rhabdomyolysis is a condition in which damaged skeletal muscle tissue breaks down rapidly. Breakdown products of damaged muscle cells are released into the bloodstream; some of these, such as the protein myoglobin, are harmful to the kidneys and may lead to kidney failure...

 or muscle destruction. Myoglobin is present in muscle
Muscle
Muscle is a contractile tissue of animals and is derived from the mesodermal layer of embryonic germ cells. Muscle cells contain contractile filaments that move past each other and change the size of the cell. They are classified as skeletal, cardiac, or smooth muscles. Their function is to...

 cells as a reserve of oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

.

Causes

Trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...

, vascular problems, venom
Venom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...

s, certain drugs and other situations can destroy or damage the muscle, releasing myoglobin to the circulation and thus to the kidneys.

Under ideal situations myoglobin will be filtered and excreted with the urine, but if too much myoglobin is released into the circulation or in case of renal problems, it can occlude the renal filtration system leading to acute tubular necrosis and acute renal insufficiency.

Other causes of myoglobinuria include:
  • McArdle's disease
  • Phosphofructokinase deficiency
    Phosphofructokinase Deficiency
    Phosphofructokinase deficiency, also known as Glycogen storage disease type VII or Tarui's disease, is metabolic disorder with autosomal recessive inheritance.It may affect humans as well as other mammals...

  • Carnitine palmitoyltransferase II deficiency
    Carnitine palmitoyltransferase II deficiency
    Carnitine palmitoyltransferase II deficiency is a metabolic disorder characterized by an enzymatic defect that prevents long-chain fatty acids from being transported into the mitochondria for utilization as an energy source....


Diagnosis

After centrifuging, the serum of myoglobinuria is clear, where the serum of hemoglobinuria
Hemoglobinuria
In medicine, hemoglobinuria or haemoglobinuria is a condition in which the oxygen transport protein hemoglobin is found in abnormally high concentrations in the urine. The condition is often associated with hemolytic anemia, in which red blood cells are destroyed, thereby increasing levels of free...

after centrifuge is pink.

External links

  • Overview on the Neuromuscular disease center website.
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