[Hepatic proliferation factor of human fetus liver cells]

It was demonstrated in this study that after ultrasonification and centrifugation of human fetus liver cells the supernatant could increase the incorporation of 3H-TdR into DNA of mice liver cells approximately 2.57 times than that of control. This proliferation effect is not species-specific, but has a relationship with supernatant content. The maximal promotion of 3H-TdR into DNA of the guinea-pig liver cells took place when the supernatant protein content was about 0.55 mg/ml. The supernatant can be divided into four components by Ultrogel A6 chromatography and the fourth component is the dominant both in protein content and in proliferation activity. SDS-polyacrylamide gel electrophoresis showed that its molecular weight is about 15,000 dalton.