Kinetics of the acute-phase reaction in rats after tumor transplantation

Transplantation of Yoshida sarcoma (solid type) and Zajdela ascites hepatoma tumors in rats induces a biphasic change in the concentration of the following five acute-phase proteins: alpha-1-acid glycoprotein; alpha-1-antitrypsin; haptoglobin; hemopexin; and ceruloplasmin. These proteins and other plasma proteins were quantitated by two-dimensional immunoelectrophoresis relative to normal serum concentrations. The elevation of most of these acute-phase proteins was greater in the second phase, during which serum levels increased continuously as the tumor burden increased until the animals died. The increase in haptoglobin concentration during the second phase was much higher in rats bearing Yoshida sarcoma than in rats bearing Zajdela tumors. Rats receiving irradiated tumor cells showed neither tumor growth nor second-phase protein changes. Significant increases in uptake of 3H-amino acids by isolated perfused livers of tumor-bearing rats provided evidence for an increase in the hepatic synthesis rates of the acute-phase proteins. Removal of the solid tumor resulted in a gradual decrease of acute-phase protein concentrations with concomitant increase in serum albumin concentration. These alterations in serum acute-phase proteins during tumor growth and after removal of the tumor may make their use attractive as biological markers of the response of the tumor-bearing animal to its tumor.