Reduced bone marrow angiogenesis in leukemic rats treated with anti–OB-R, but not with anticasein mAb.

(A) Representative fields of histologic cross sections from bone marrow of a healthy (i) and a leukemic (ii) rat. The microvessels were identified with an anti–von Willebrand mAb (red stain). Note the higher microvessel density in leukemic versus normal marrow. Magnification × 500. (B) Pooled data of leukemic rats treated with saline (control) or with anti–OB-R or anticasein mAb. Values are based on staining with an anti-VWF mAb and an anti-PECAM mAb, and presented as means + SEM; n = 8 rats; *P < .05 compared with control.