Serum creatine kinase isoenzyme

CK consists of two subunits, M and B, which are combined into three isoenzymes, CK-BB, CK-MM, and CK-MB. There is another isoenzyme in the mitochondria of the cell, called CK-Mt. CK-BB mainly exists in brain, prostate and other organs, CK-MM mainly exists in bones and myocardium, CK-MB mainly exists in myocardium, most of normal human blood is CK-MM, a small amount of CK-MB, and BB is rare.