Add to ORKGWe developed an efficient enzyme-linked immunosorbent assay (ELISA) system for measurement of human liver-type arginase in serum. A conjugate of the Fab ’ fragment of anti-human liver (recombinant) arginase lgG and horseradish peroxidase was used as the second anti-body. This assay is highly specific, sensitive, and repro-ducible, enabling us to detect arginase at concentrations as low as several micrograms per liter without any prior processing of serum. The reaction is linear up to 200 p.g/L. The arginase concentration in serum, as deter-mined by this method, increased markedly and tempo-rarily at the time of surgical operation or later injury to the liver. The increase was accompanied or followed by increases in serum concentrations of a...