No one has counted the enzymes in the human organism, and probably their profuse number can only be estimated from the restrictions the finite mass of genetic material imposes. Still, nu­ merous catalytic activities have been identified and investigated for their clinical relevance. After one century of such research, surprisingly, only a handful of enzymes has survived the stern trial of clinical application to find regular medical use. Dis­ regarding genetic defects, most of the diagnostically used en­ zymes participate in metabolic conversions fundamental to life: the utilization, transfer or fixation of vital nutrients or of cheJ,llical energy. Creatine kinase is central to the function of the mitochond­ rion, the cellular power generator. The wider distribution of this enzyme is linked to tissues whose physiology crucially relies on an adaptable supply of energy, notably skeletal muscle, the brain, and the heart. Just as these three tissues vary in their pre­ ference for different energy sources, each produces a different isoenzyme of creatine kinase. Accordingly, the finding of elevat­ ed creatine kinase activity in blood can lead to a variety of interpretations, but in practice the diagnosis of acute myocardial infarction is the major consideration.

1 Introduction.- 1.1 Creatine Kinase in Muscular Metabolism.- 1.2 Creatine Kinase in Clinical Chemistry.- 1.3 Creatine Kinase Isoenzymes.- 1.4 Scope and Summary of this Book.- 2 Creatine Kinase Isoenzymes.- 2.1 The Cytoplasmic Isoenzymes from Human Tissues.- 2.2 The Mitochondrial Isoenzyme from Human Heart Muscle.- 3 Methods for Differentiation and Quantitation of Creatine Kinase Isoenzymes.- 3.1 Methods for Determination of Creatine Kinase Activity.- 3.2 Differentiation of Isoenzymes by Non Immunological Methods..- 3.3 Measurement of Isoenzyme Activity by Immunological Methods..- 3.4 Experimental Comparison of Methods for Differentiation of Isoenzymes.- 3.5 Measurement of Isoenzyme Concentration by Immunoassay..- 4 Tissue Specific and Subcellular Distribution of Creatine Kinase Isoenzymes.- 4.1 Tissue Specific Distribution.- 4.2 Subcellular Distribution.- 4.3 Ontogeny.- 5 Clinical Results: Myocardium.- 5.1 Myocardial Infarction.- 5.2 Infarct Size Estimation from Serial Analyses of CK and Isoenzyme Activity..- 5.3 Perioperative Infarction.- 5.4 Complications, Differential Diagnosis, and Diagnostic/ Therapeutic Procedures Associated with Myocardial Infarction..- 5.5 Heart Failure and Inflammation..- 6 Clinical Results: Skeletal Muscle.- 6.1 Direct Skeletal Muscle Damage..- 6.2 Muscular Dystrophies..- 6.3 Hypothyroidism..- 6.4 Various Muscular Diseases..- 6.5 Collagen Diseases..- 7 Clinical Results: Central Nervous System.- 7.1 Cerebral Diseases..- 7.2 Acute Psychosis..- 8 Clinical Results: Gastrointestinal Tract, Liver, and Pancreas..- 8.1 Gastrointestinal Tract Diseases.- 8.2 Liver Diseases.- 8.3 Pancreatic Diseases.- 9 Clinical Results: Kidney and Urogenital Tract..- 9.1 Renal Diseases.- 9.2 Prostatic Carcinoma.- 10 Clinical Results: Intoxication.- 10.1 Exogenous Intoxication..- 10.2 Alcoholism..- 11 Clinical Results: Perinatal Period..- 11.1 Enzymes in Pregnancy.- 11.2 Myometrium and Placenta.- 11.3 Maternal Serum During Pregnancy, Labor, and After Delivery.- 11.4 Cord Blood.- 11.5 Discussion.- 11.6 Summary.- 12 The Creatine Kinase 242 BB Isoenzyme..- 12.1 Distribution ofCK-BB in Human Tissues.- 12.2 Problems in Evaluation of Published Data.- 12.3 Serum CK-BB Activity.- 12.4 CK-BB in Cerebrospinal Fluid.- 12.5 "Idiopathic" and "Macro" Serum CK-BB.- 12.6 Genetic Variants.- 12.7 Summary.- References.- List of Abbreviations.