Effects of Recombinant Human Macrophage Colony-Stimulating Factor on Plasma Cholesterol Levels

Recombinant human macrophage colony-stimulating factor (rhM-CSF) is a hematopoietic growth factor that stimulates the growth, differentiation, proliferation, and activation of cells of the monocyte/macrophage lineage. rhM-CSF was administered t o rabbits and nonhuman primates to evaluate effects on cholesterol homeostasis. Decreases in plasma cholesterol concentrations were observed during rhM-CSF administration. The observed mean (kSD) decreases over a range of doses in nonhuman primates receiving rhM-CSF by continuous intravenous infusion (CIVI) or intravenous bolus (IVB) injection were approximately 16% f 8% and 43% f 10%. respectively. Low-density lipoprotein (LDL) cholesterol levels decreased 55% -+ 9% from pretreatment baseline values in the animals receiving rhM-CSF by IVB. Normocholesterolemic New Zealand white rabbits receiving rhM-CSF over a range of doses by ClVl showed a decrease from