creatine kinase (CK)

(redirected from creatine kinase CK)

creatine kinase (CK)

syn creatine phosphokinase (CPK) enzyme which catalyses transfer of phosphate group from creatine phosphate to ADP, producing ATP and creatine. Occurs as three isoenzymes, originating in brain, skeletal muscle and cardiac muscle. creatine kinase test estimates the myocardial isoenzyme in the blood: an increased level indicates acute myocardial infarction. If the test follows strenuous exercise, especially if it had a large eccentric component, distinction from the skeletal muscle isoenzyme is critical. See also muscle enzymes.


a nonprotein nitrogen substance synthesized in the body from three amino acids: arginine, glycine (aminoacetic acid) and methionine. Creatine readily combines with phosphate to form phosphocreatine, or creatine phosphate, which is present in muscle, where it serves as the storage form of high-energy phosphate necessary for intense muscle contraction.

creatine kinase (CK)
an organ-specific enzyme catalyzing the transfer of a phosphate group from phosphocreatine to ATP. It has three isoenzymes: CK1, found primarily in the brain; CK2, found in the myocardium; and CK3, found in both skeletal muscle and the myocardium. In humans, the presence of CK2 in the blood is useful in diagnosing a recent myocardial infarction, but in animals CK3 is most commonly increased related to muscle damage. Called also creatine phosphokinase, Lohmann's enzyme.
creatine phosphate
see creatine (above).
creatine phosphokinase
called also CPK; see creatine kinase (above).