ABSTRACT
<p><b>OBJECTIVE</b>To characterize the differential and proliferative activities of FLK-1(+) cells derived from mouse fetal liver.</p><p><b>METHOD</b>The FLK-1(+) fraction were enriched from the fetal liver using immunomagnetic method and their differential and proliferative activities were examined in culture medium and in vivo via transplantation of FLK-1(+) cells into the inferior pole of the spleen of nine-week-old male C57 BL/6 mice after two-thirds hepatectomy.</p><p><b>RESULTS</b>In response to growth factors, FLK-1(+) cells expressed typical lineage-specific markers for vascular endothelial cells, smooth muscle cells. Intrahepatic implantation of FLK-1(+) cells resulted in the formation of blood vessels in the fibrous capsule of partially hepatectomized liver.</p><p><b>CONCLUSION</b>These results indicate that FLK-1(+) cells derived from mouse fetal liver could differentiate into endothelial cells and smooth muscle cells and they may serve as potential stem cells for clinical cell-based therapy.</p>