Cholinesterase

Cholinesterase ( ChE ) are enzymes that cleave choline esters. You are in the metabolism of multicellular animals essential to reduce these substances, especially of acetylcholine, a neurotransmitter. Cholinesterases also occur in plants, fungi and bacteria.

There are two distinct cholinesterases in animals. In evolutionary acetylcholinesterase has in the first multicellular organisms formed first. Probably by copy of its gene ( gene duplication ) was then compared with the first chordates the pseudocholinesterase, which has a wider range of substrates. In humans, the enzymes are synthesized in hepatocytes and secreted into the blood plasma. There they split acetylcholine, butyrylcholine and other acylcholines or Thiocholine.

Laboratory diagnostics

In the laboratory diagnostics, the activity of cholinesterases from heparin plasma or serum is measured by the progress of liver disease to be monitored.

Reference range for measurements at 37 ° C: 4.9 to 12.0 kU / l

In a patient with liver disease is a decrease of cholinesterase in that the synthetic capacity of the liver cells is limited, that is, that the liver produces less proteins. Due to the long biological half-life of 12-14 days, the cholinesterase activity in acute liver disease is often within the reference range. The importance lies mainly in the course of chronic hepatitis or liver cirrhosis.

Because there are several genetic variants of this enzyme, which are not all equally active, are found in rarer cases, even in healthy people Cholinesterasemangelzustände. Medically relevant is this in anesthesia ( general anesthesia ) in which muscle relaxants are used with the drug succinylcholine. These are broken down by people with Cholinesterasemangel (depending on severity ) more slowly, which can lead to longer -lasting apnea and immobilizes. With the help of dibucaine number ( cholinesterase activity after inhibition with dibucaine ) this can be clarified.