Fibrinogen synthesis in the isolated perfused rat liver: stimulation by a humoral factor associated with trauma

Fibrinogen synthesis was measured by the [14C]carbonate method in isolated rat livers perfused with blood from normal rats and rats injected with turpentine 1, 5, and 16 hr before bleeding. Five- and 16-hr blood increased synthesis 2-fold, compared with normal and 1-hr blood. Turpentine injection caused a 10-fold rise in fibrinogen fragment D immunoreactivity (measured by serum radioimmunoassay) 5 and 16 hr after injection, compared with normal rats, and rats bled 1 hr after turpentine injection. Isolation of fibrinogen-related antigen by immunoaffinity chromatography, followed by polyacrylamide gel electrophoresis, revealed substantial increases in fibrinogen-related protein in 5- and 16-hr blood. The largest relative increase was in protein with electrophoretic mobility similar to that of fragment D1. These studies demonstrate the presence of a transferable blood factor which, produced in response to injury, stimulates fibrinogen synthesis by the liver. They lend support to the possibility that this factor may be fragment D1 or one or more other derivatives of the D domain of the fibrinogen molecule.