Creatine Kinase

Creatine kinase (CK), also known as phosphocreatine kinase or creatine phosphokinase (CPK) is an enzyme (EC 2.7.3.2) expressed by various tissue types. Its function is the catalysis of the conversion of creatine to phosphocreatine, consuming adenosine triphosphate (ATP) and generating adenosine diphosphate (ADP) and the reverse reaction. In tissues that consume ATP rapidly, especially skeletal muscle, but also brain and smooth muscle, phosphocreatine serves as an energy reservoir for the rapid regeneration of ATP, the major source of energy in biochemical reactions. Image File history File links Download high resolution version (1024x1032, 120 KB) Please see the file description page for further information. ... Image File history File links Download high resolution version (1024x1032, 120 KB) Please see the file description page for further information. ... Ribbon diagram of the enzyme TIM, surrounded by the space-filling model of the protein. ... The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ... Creatine is a nitrogenous organic acid that naturally occurs in vertebrates and helps to supply energy to muscle cells. ... Phosphocreatine, also known as creatine phosphate or PCr, is a phosphorylated creatine molecule that is an important energy store in skeletal muscle. ... Adenosine 5-triphosphate (ATP), discovered in 1929 by Karl Lohmann,[1] is a multifunctional nucleotide primarily known in biochemistry as the molecular currency of intracellular energy transfer. ... Adenosine diphosphate, abbreviated ADP, is a nucleotide. ... A reversible reaction is a chemical reaction that may proceed in both the forward and reverse directions. ... A top-down view of skeletal muscle Skeletal muscle is a type of striated muscle, attached to the skeleton. ... In animals, the brain, or encephalon (Greek for in the head), is the control center of the central nervous system. ... Cultured Smooth muscle of the aorta. ...

Types

In most of the cell, the CK enzyme consists of two subunits, which can be either B (brain type) or M (muscle type). There are, therefore, three different isoenzymes: CK-MM, CK-BB and CK-MB. The genes for these subunits are located on different chromosomes: B on 14q32 and M on 19q13. In addition to those, there are two mitochondrial creatine kinases, the ubiquitous and sarcomeric form. Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... Isozymes, (or isoenzymes) are isoforms (closely related variants) of enzymes. ... Figure 1: A representation of a condensed eukaryotic chromosome, as seen during cell division. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ...

Isoenzyme patterns differ in tissues. CK-BB occurs mainly in tissues, and its levels do rarely have any significance in bloodstream. Skeletal muscle expresses CK-MM (98%) and CK-MB at low levels (1%) in muscle. The myocardium (heart muscle), in contrast, expresses CK-MM at 70% and CK-MB at 30%. Hugo is a masculine name. ... The Entrez logo The Entrez Global Query Cross-Database Search System allows access to databases at the National Center for Biotechnology Information (NCBI) website. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The National Center for Biotechnology Information (NCBI) is part of the US National Library of Medicine (NLM), which is a branch of the US National Institutes of Health. ... Swiss-Prot is a curated biological database of protein sequences created in 1986 by Amos Bairoch during his PhD and developed by the Swiss Institute of Bioinformatics and the European Bioinformatics Institute. ... The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ... Short and long arms Chromosome. ... Chromosome 14 is one of the 23 pairs of chromosomes in humans. ... Hugo is a masculine name. ... The Entrez logo The Entrez Global Query Cross-Database Search System allows access to databases at the National Center for Biotechnology Information (NCBI) website. ... The Mendelian Inheritance in Man project is a database that catalogues all the known diseases with a genetic component, and - when possible - links them to the relevant genes in the human genome. ... The National Center for Biotechnology Information (NCBI) is part of the US National Library of Medicine (NLM), which is a branch of the US National Institutes of Health. ... Swiss-Prot is a curated biological database of protein sequences created in 1986 by Amos Bairoch during his PhD and developed by the Swiss Institute of Bioinformatics and the European Bioinformatics Institute. ... The Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. ... Short and long arms Chromosome. ... Chromosome 19 is one of the 23 pairs of chromosomes in humans. ... Myocardium is the muscular tissue of the heart. ...

Predominate Creatine Kinase Expresion

• MM - Skeletal Muscle
• MB - Cardiac Muscle
• BB - Brain Tissue

Laboratory testing

CK is often determined routinely in emergency patients. In addition, it is determined specifically in patients with chest pain and acute renal failure. Normal values are usually between 25 and 200 U/L. This test is not specific for the type of CK that is elevated. In medicine, chest pain is a symptom of a number of serious conditions and is generally considered a medical emergency, unless the patient is a known angina pectoris sufferer and the symptoms are familiar (appearing at exertion and resolving at rest, known as stable angina). // Causes Cardiopulmonary Important cardiovascular and... The litre or liter (U.S. spelling, see spelling differences) is a unit of volume. ...

Elevation of CK is an indication of damage to muscle. It is therefore indicative of injury, rhabdomyolysis, myocardial infarction, myositis, myocarditis, malignant hyperthermia and neuroleptic malignant syndrome. It is also seen in McLeod syndrome and hypothyroidism. The use of statin medications, which are commonly used to decrease serum cholesterol levels, may be associated with elevation of the CPK level in about 1% of the patients taking these medications, and with actual muscle damage in a much smaller proportion. It has been suggested that this article or section be merged into Muscular system. ... Injury is damage or harm caused to the structure or function of the body caused by an outside agent or force, which may be physical or chemical. ... Rhabdomyolysis is the breakdown of skeletal muscle due to injury, either mechanical, physical or chemical. ... Acute myocardial infarction (AMI or MI), commonly known as a heart attack, is a clinical event that occurs when the blood supply to a part of the heart is interrupted. ... In medicine (cardiology), myocarditis is inflammation of the myocardium, the muscular part of the heart. ... Malignant hyperthermia (MH or MHS for malignant hyperthermia syndrome, or malignant hyperpyrexia due to anesthesia) is a life-threatening condition resulting from a genetic sensitivity of skeletal muscles to volatile anaesthetics and depolarizing neuromuscular blocking drugs that occurs during or after anaesthesia. ... Neuroleptic malignant syndrome (NMS) is a life-threatening, neurological disorder most often caused by an adverse reaction to neuroleptic or antipsychotic drugs. ... McLeod syndrome (or McLeod phenomenon) is a genetic disorder caused by presence of the McLeod phenotype, a recessive anomaly on the X chromosome which alters production of XK protein (a precursor of Kell antigens on the surface of red blood cells). ... This article or section does not cite its references or sources. ... Lovastatin, the first statin to be marketed The statins (or HMG-CoA reductase inhibitors) form a class of hypolipidemic agents, used as pharmaceuticals to lower cholesterol levels in people at risk for cardiovascular disease because of hypercholesterolemia. ...

Lowered CK can be an indication of alcoholic liver disease and rheumatoid arthritis. Rheumatoid arthritis (RA) is traditionally considered a chronic, inflammatory autoimmune disorder that causes the immune system to attack the joints. ...

Isoenzyme determination has been used extensively as an indication for myocardial damage in heart attacks. Troponin measurement has largely replaced this in many hospitals, although some centres still rely on CK-MB. Troponin is a protein complex that confers calcium sensitivity to muscle cells. ...

See also

• Reference ranges for common blood tests

A reference range is a set of values used by a health professional to interpret a set of medical test results. ...

References

• Mendelian Inheritance in Man (OMIM) 123310 (CK-M chain) and Mendelian Inheritance in Man (OMIM) 123280 (CK-B chain)
• Simply stated