fig4

Figure 4. Autoradiographs of SDS-PAGE-analysis of a biosynthetically, radio-actively labelled major positive acute-phase-protein (SAA), a minor positive acute-phase (factor B) and of the major negative acute-phase protein (albumin) immunoprecipitated from the same sample of supernatant from hepatocyte cultures treated with different amounts of recombinant IL1. Line 5 in panel A and lines 7-9 are negative controls. The relative abundance of the different proteins released into the supernatant is demonstrated by the time of exposure of the film to the filter containing the immunoprecipitated radioactive protein. The shortest time of exposure time was for albumin (24 h) and the longest was SAA (21 days). While synthesis of albumin was inhibited by increasing doses of human recombinant IL-1, synthesis of factor B and of SAA were increased at the same time in the hepatocyte reproducing the process taking place in the liver in vivo during an acute phase situation. It is understandable that the serum concentrations of the acute-phase cytokines produced at extrahepatic sites has to be quite high to induce changes of protein synthesis in the liver until these can become measurable. This is also the case for those proteins whose constitutive gene-expression is almost undetectable, as is the case for SAA or CRP in humans. SAA: serum amyloid A. 1985;162:930-42. (reprinted with permission)^[49]