The granulopoietic effect of human urinary colony stimulating factor on normal and cyclophosphamide treated mice

A practically endotoxin-free colony stimulating factor from human urine (CSFHU) was prepared and its granulopoietic effect on normal and cyclophosphamide treated mice was examined. When normal C57BL/6N mice were injected intraperitoneally with 2.5 X 10(6) units/kg of the CSFHU daily for a 5-day period, the numbers of progenitor cells (CFUC) in the femur and spleen were significantly increased. The CFUC in the femur and spleen reached a maximum at day 3 (270%) and day 5 (250%) after the initial injection, respectively. The increase in number of CFUC in the femur exhibited a dose-dependency with respect to the CSFHU and a significant increase was observed even at 4 X 10(5) U/kg (P less than 0.05). However, neither granulocytosis nor monocytosis occurred in normal C57BL/6N mice injected with the CSFHU. In cyclophosphamide induced leukopenic C3H/HeN mice, daily injections of the CSFHU at 2.5 X 10(6) U/kg for 5 days stimulated the restorative granulocyte production (P less than 0.05) as well as the CFUC recovery in both the femur and spleen. These findings suggested that the CSFHU might be involved in granulocyte production in vivo.