The mechanisms relating to increases in plasma enzymes and isoenzymes in diseases of animals.

Changes in plasma or serum enzymes and isoenzymes are useful indicators of tissue damage in many diseases. Enzyme increases are usually related to leakage of enzymes from damaged cells. The amount of increase depends on factors such as the concentration of enzyme in the cells, the rate of leakage of enzyme from cells and the rate of clearance of enzyme from plasma. There are important species variations in the tissue concentrations and plasma clearance rates of enzymes and isoenzymes.