This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Enzymes, Subject name: Biochemistry
Myocardial infarction is associated with increased of 
Select and explain. 
A. CPK, B. CPK-MM, C. CPK-MB, D. CPK - BB
C: CPK-MB
Answer: C: CPK-MB 
Explanation: C. i.e. (CPK - MB) (III - U. Satyanarayan 3rd) (599- Rana Shinde 7th)CPK exists as three isoenzyme - Each isoenzyme is a dimmer composed of two subunits - M (muscle) or B (brain) or bothIso enzymeSubunitTissue of originCPK,BBBraincpk2MBHeartCPK3MMSkeletal muscle* CPK2- MB is the earliest reliable indication of myocardial infarction* Troponins are more sensitive and specific*** CPK - NOT found in RB cells and it level is not affected by haemolysis* Normal value - 4 - 60 IU/L (at 37degC)