Systemic PGE₂ treatment alters bone marrow microarchitecture. Femora and tibiae of vehicle- (VEH) and PGE₂-treated mice were analyzed by micro-CT and histology. Three-dimensional reconstructions of representative scanned femora (A-B) and tibiae (C-D) focusing on trabecular bone. Quantification of the trabecular number (E,G) and trabecular spacing (F,H) (n = 4/group). High- (I-J) and low-power (K-L) representative images of histologic slides stained with hematoxylin and eosin, focusing on the metaphyseal region of the distal femur from vehicle- and PGE₂-treated mice. Arrowheads indicate disrupted trabeculae in the PGE₂-treated mice (J). **P ≤ .01; ***P ≤ .001.