RT Journal Article SR Electronic T1 Creatine kinase isoenzymes in human cerebrospinal fluid and brain. JF Clinical Chemistry JO Clin. Chem. FD American Association for Clinical Chemistry SP 1804 OP 1806 VO 30 IS 11 A1 Chandler, W L A1 Clayson, K J A1 Longstreth, W T A1 Fine, J S YR 1984 UL http://clinchem.aaccjnls.org/content/30/11/1804.abstract AB Extracts of normal brains obtained at autopsy and cerebrospinal fluid (CSF) from patients with global brain ischemia were analyzed for creatine kinase (CK; EC 2.7.3.2) isoenzymes. We used both qualitative and quantitative assays (electrophoresis and immunoinhibition). Brain extracts contained CK-BB isoenzyme and mitochondrial CK. In 54 CSF samples free of blood contamination and with total activities ranging from 7 to 2010 U/L (mean 202 U/L), virtually all of the CK activity was due to CK-BB, and none to CK-MM or CK-MB. We conclude that brain contains CK-BB and mitochondrial CK, but lacks CK-MM and CK-MB. After cardiac arrest, CK-BB is released into the CSF. Any CK-MM in the CSF is probably from blood contamination, in which case immunoinhibition with anti-CK-M antibodies accurately quantifies CK-BB.