Enzymes in Blood Plasma gives a comprehensive account of the current state of research and practical application of biochemistry and biology, as well as the pathology and clinical aspects of plasma enzymes. Enzymes in blood plasma, for reasons of principle and methods, are not limited to plasma-specific enzymes, which are only briefly mentioned. Emphasis will rather be placed on plasma-nonspecific enzymes, i.e., enzymes of identical properties in plasma and serum. Their action is, for technical reasons, generally determined in serum. The enzymes in plasma will be stressed in this presentation, but the situation in other extracellular spaces and even extracorporeal areas such as urine, excreta, and feces will be included. There exists no basic difference of enzyme function in these biological areas. Many of the findings reported in this volume were obtained with the old units and methods, rather than the International Unit. For this reason, the section dealing with methods includes a table for conversion, which can be used for comparison of data, insofar as these data were obtained under optimalconditions of measurement.