Description
CK-MB is intended to measure the activity of isoenzyme CK-MB in human serum. Creatine kinases are dimeric molecules composed of M and B subunits and exist as the isoenzymes MM, MB, and BB. The subunits M and B are immunologically distinct; CK-MM and CK-MB are distributed primarily in the skeletal muscle and heart muscle, respectively. While CK-BB is present mainly in the brain and in tissues composed of smooth muscle. Following acute myocardial infarction, CK-MB activity increases significantly and this elevation is highly specific for the laboratory diagnosis of myocardial infarction. Although total CK activity usually increases following myocardial infarction, in some patients only the CK-MB activity increases, while the total CK remains in the normal range.