ALUMINUM INHIBITS BONE NODULE FORMATION AND CALCIFICATION INVITRO

Cells isolated from neonatal mouse calvariae can be induced to form mi neralized nodules after exposure to ascorbic acid and beta-glycerophos phate. To determine whether aluminum inhibits nodule formation and sub sequent mineralization, cells isolated from neonatal mouse calvariae w ere induced to form nodules and incubated with increasing concentratio ns of aluminum (10(-7) to 10(-5) M). Compared with control and 10(-7) M aluminum-supplemented cultures, the number of nodules formed and the number of nodules calcified were reduced in cells incubated with 10(- 6) and 10(-5) M aluminum. The cumulative net calcium uptake into the n odules and their final calcium content were also decreased with 10(-6) and 10(-5) M aluminum. After 10 and 18 days of incubation, aluminum d id not affect DNA synthesis or release of alkaline phosphatase but sig nificantly inhibited collagen production. Thus aluminum induced a dose -dependent inhibition of nodule formation and calcification that may b e related to its inhibition of collagen production.