Kupffer cell regulation of fibrinogen synthesis in hepatocytes

Isolated rat liver macrophages (Kupffer cells) produce a factor(s) which stimulates fibrinogen synthesis 5-8 fold in hepatocyte cultures. The production of the stimulatory factor reached maximum during the first 24 hours the cells were in culture. When the cell culture medium was chromatographed on a calibrated Sephadex G-75 column the major activity peak eluted in the size range of 25,000-30,000 daltons. Taken together these results demonstrate that in addition to their well known phagocytic function, Kupffer cells secrete factor(s) that can significantly increase fibrinogen synthesis.