Serum antitrypsin synthesis by the isolated perfused rat liver.

The isolated perfused rat liver synthesizes antitrypsin activity in a linear fashion as long as 24 hr. The rate of synthesis may be ten times the rate necessary for physiologic levels in vivo. These data are compatible with the liver as the principal site of synthesis of serum antitryptic activity in the rat. The antitrypsin activity of the rat perfusate resembles that of normal human plasma in liability to heat (56 degrees) and to acid (below pH 6) and in apparent molecular size (elution from Sephadex G-200).