Synthesis of all plasma protein fractions except gamma globulins by the liver; the use of zone electrophoresis and lysine-epsilon-C14 to define the plasma proteins synthesized by the isolated perfused liver.

Lysine-epsilon-C(14)-labeled plasma proteins produced by the normal rat and the isolated perfused rat liver have been fractionated by preparative zone electrophoresis. The isolated perfused liver incorporates lysine-epsilon-C(14) into the plasma albumin, alpha globulin, and beta globulin (including fibrinogen) fractions. No significant C(14) incorporation into the trichloracetic acid-precipitable proteins of the gamma globulin fraction was observed. Presumptive evidence indicates that the alpha globulins turn over more rapidly than any other major plasma protein fraction. The increased production of gamma globulins in liver disease is discussed.