Figure 3.

Treatment of Abcc6^−/− mice, a model of pseudoxanthoma elasticum, with etidronate, a bisphosphonate analog of inorganic pyrophosphate (PPi), prevents ectopic mineralization. A: Bisphosphonates (BPs) are stable analogs of PPi because of the presence of a carbon bond, instead of oxygen, and the presence of side chains (R1 and R2). B: Top left panel:Abcc6^−/− mice at 12 weeks of age demonstrate extensive mineralization of the connective sheath of vibrissae in the muzzle skin, as demonstrated by Alizarin Red stain. Administration of etidronate either orally (p.o.; top middle panel) or by s.c. injections (top right panel) during weeks 4 to 12 significantly reduced the mineral deposits. Administration of etidronate also significantly increased the density of trabecular bone both in male (middle row) and in female (bottom row) mice.

Adapted with permission from Li et al.³⁴