Basic fibroblast growth factor is hepatotropic for rat liver in regeneration

A role for fibroblast growth factor in liver regeneration has recently been suggested. In this study we followed the intravenous delivery of recombinant human [125I]basic fibroblast growth factor to the liver of rats following 68% partial hepatectomy. The concentration of [125I]basic fibroblast growth factor was higher in the liver (mean±SD, 6.8±0.89% of injected dose) and the kidney (6.7±0.2%) of sham-operated rats than in the spleen (2.8±0.45%). It increased threefold in the liver only, soon after 68% partial hepatectomy (20.3±5.3%, p<0.001), and remained high for the first 24 h. We also studied the effect of basic fibroblast growth factor injection on the rate of [3H]thymidine incorporation into liver DNA in rats subjected to either 21% or 68% partial hepatectomy. A significant increase was seen after intramesenteric injection of 500 ng basic fibroblast growth factor into rats subjected to 21% partial hepatectomy (23.5±7.3 cpm/pg DNA) compared to saline-injected rats (14.5±6.4 cpm/,μg DNA, p=0.034). A dose of 5000–25 000 ng injected into a peripheral vein resulted in higher thymidine incorporation than in saline-injected control rats (36.9±12.7 and 9.7±6.1 cpm/,ug DNA, respectively; p<0.0001). No significant effect was seen after 68% partial hepatectomy. Autoradiography showed that the hepatocytes were the predominant labelled cells early after hepatectomy and basic fibroblast growth factor injection. We conclude that basic fibroblast growth factor uptake by the liver is increased after 68% partial hepatectomy and that basic fibroblast growth factor is mitogenic to liver parenchymal cells early after 21% partial hepatectomy.