Effects of AZT on BMD and bone histomorphometry in mice. Mice, 5 months old, were orally fed PBS (n = 6, control) or AZT (n 5, AZT 100 mg/kg/day) for 30 days. (A) Bone mineral density (BMD) was measured by=DEXA. (B) Spines were fixed, decalcificated, and stained with trichrome. Histomorphometry was analyzed in three vertebrae of each animal. Osteoclast parameters included number (OcN) and surface (OcS) of osteoclasts. Osteoblast parameters included number (ObN) and surface (ObS) of osteoblasts. All parameters were compared to the control values, and reported as percentage change induced by AZT. The results were mean ± SE. P values are compared to controls.