Plasma and Erythrocyte Enzymes in Phenylhydrazine Anemia

Dehydrogenases and transaminases occur in high activities in the erythrocyte when compared to the plasma in which the erythrocyte is suspended. Destruction of the erythrocyte with phenylhydrazine does not release any enzyme activity into the plasma. SEVERAL YEARS AGO LaDue (2) made the iiiteresting observation that soon after myocardial infarction the plasma glutamic oxalacetie tramis-ammase is increased, reaches a peak within a few days, and then re-turns to normal. This observation stimulated a new area of clinical in-terest ill diseases related to infarction and necrosis as manifested ill plasma enzymes changes. The source of this increased plasma enzyme activity in disease has become of interest to the clinical chemist. Is this activity newly formed, or is the enzyme system transported from the necrotic tissue to the cir-culating plasma to be excreted or inactivated Experimental work has made it obvious that these enzymes are not excreted into tile urine. Where or how they are inactivated would he more difficult to demon-strate. Transport from necrotic tissue to plasma assumes that the “leaching ” process transfers the complete kinetic system from the fixed tissue phase to the circulating plasma phase. The complexity of the problem is of course inherent in the complexity of protein structure and synthesis and the kinetics of the enzyme systems