creatine phosphokinase

creatine phosphokinase.

See creatine kinase.

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creatine

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.

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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).