Net Biosynthesis of Antithrombin III by the Isolated Rat Liver Perfused for 12--24 Hours. Compared with Rat Fibrinogen and alpha -2 (Acute Phase) Globulin, Antithrombin III Is Not an Acute Phase Protein

摘要

Antithrombin III- heparin cofactor has been isolated from normal rat plasma, purified to homogeniety on acrylamide gel electrophoresis and used to prepare a monospecific antiserum in rabbits. Measurements of rat AT-III were made by a single radial immunodiffusion assay. Net synthesis of AT-III was investigated during 12 or 24 hour perfusions of the isolated rat liver. In perfusions performed under basal conditions cumulative synthesis of AT-III was observed to occur at a rate sufficient to replace the total circulating plasma AT-III in about 6 hours. In perfusions performed under full supplementation conditions which greatly enhanced synthesis of fibrinogen and alpha -2 (acute phase) globulin (known acute phase reactant proteins) net synthesis of AT-III was not significantly greater than that observed in control perfusions. Although these prolonged perfusion studies conclusively demonstrate net synthesis of AT-III by the isolated rat liver, they afford no evidence that this protein is an acute phase reactant. (ERA citation 04:039638)