Saos2 cells (A) were plated at 50,000 cells/cm2, endothelial cells (C and D) were plated at 30,000 cells/cm2, grown to 80~90% confluence and were subsequently treated with vehicle or PTHrP(1–34) at 10 nM for 4h after serum starvation. PTHrP antagonist, PTHrP(7–34) (2 µM) was added 30 min before PTHrP(1–34) treatment. Primary mouse osteoblasts (B) were treated with PTHrP or vehicle for 4h without serum starvation. CCL2 levels in the media were measured by ELISA. Data are shown as mean ± SEM. (** p<0.01 versus vehicle control and * p<0.05 versus PTHrP treated group, n=3)