Inorganic pyrophosphate (PP i) produced by cells inhibits mineralization by binding to
crystals. Its ubiquitous presence is thought to prevent" soft" tissues from mineralizing,
whereas its degradation to P i in bones and teeth by tissue-nonspecific alkaline
phosphatase (Tnap, Tnsalp, Alpl, Akp2) may facilitate crystal growth. Whereas the crystal
binding properties of PP i are largely understood, less is known about its effects on
osteoblast activity. We have used MC3T3-E1 osteoblast cultures to investigate the effect of …