Serum lactic acid dehydrogenase isozyme determination in myocardial infarction.

Introduction The principle of electrophoresis is known to be of great use in today's medicine and an expanding literature on this subject supports this view. Various methods for the electrophoretic separation of charged molecules have been developed in the past 15 years. Immunological and physicochemical studies have further increased knowledge of these electrophoretic fractions. On this principle, Vesell & Bearn (1957) and Sayre & Hill (1957) demonstrated that lactic acid dehydrogenase (LDH) exists in multiple electrophoretically distinct forms in human serum. These physically separable molecular forms, having similar enzymatic activities, are known as isozymes (Markert & Moller, 1959). Various techniques have been employed and there is ample evidence that the LDH in human tissues consists of five isozymes and their activity can be studied in serum (Wieme, 1959; Hess & Walter, 1961; Wroblewski, Ross & Gregory, 1960; Hill, 1961). In addition it has been shown that certain isozymes originatt. predominantly from certain tissues (Wroblewski et al., 1960; Wieme & Van Maercke, 1961; Vesell, 1961; Wroblewski & Gregory, 1961; Nisselbaum & Bodansky, 1961). Lactic acid dehydrogenase isozyme 1 (LDH1) has been found to arise specifically from cardiac muscle. The tissue specificity of LDH isozymes is as follows: