Leptin promotes in vitro growth of bone marrow cells from healthy BN rats, but not from leukemic rats.

Bone marrow cells from healthy BN rats (A) and leukemic rats (B) were given either leptin (10 ng/mL), anti–OB-R (10 μg/mL), a combination of leptin (10 ng/mL) and anti–OB-R (10 μg/mL), or cyclophosphamide (Cyclo; 30 μg/mL). Values represent means + SEM; n = 8. The asterisk denotes significantly lower values compared with the control cells (no compound added), whereas the plus sign denotes a significantly higher value.