Effect of alkaline-phosphatase inhibition by 1-p-bromotetramisole on the formation of trichloroacetic acid-[32P]-insoluble phosphate from inorganic [32P]-phosphate and [32P]-pyrophosphate in non-mineralizing and mineralizing hamster molar tooth-germs in vitro.
In culture, 1-p-bromotetramisole (pBTM), a specific inhibitor of alkaline phosphatase, significantly inhibited the formation of trichloroacetic acid (TCA)-insoluble [32P]-phosphate from inorganic [32P]-phosphate in the proliferating non-mineralizing second (M2) maxillary molar germs but had no effect in the actively mineralizing first (M1) germs. Addition of 10(-5) M inorganic pyrophosphate in the culture medium with a [32P]-phosphate label increased the inhibition of the formation of TCA-insoluble [32P]-phosphate in the M2. pBTM almost completely inhibited the formation of TCA-insoluble [32P]-phosphate from inorganic [32P]-pyrophosphate in the non-mineralizing M2. In the actively mineralizing M1, the compound significantly inhibited but did not abolish the formation of TCA-insoluble phosphate. These results confirm earlier biochemical findings that alkaline phosphatase possesses a pyrophosphatase activity probably related to the turnover of phosphorylated macromolecules necessary for cell differentiation and proliferation.
Lyaruu
D M
DM
Department of Oral Cell Biology, School of Dentistry, Vrije Universiteit, Amsterdam, The Netherlands.
Wöltgens
J H
JH
Bervoets
T J
TJ
D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors*; D000818:Animals; D006224:Cricetinae; D011756:Diphosphates / Q000378:metabolism; D008647:Mesocricetus; D008963:Molar; D010710:Phosphates / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D013773:Tetramisole / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors; D014074:Tooth Calcification; D014083:Tooth Germ / Q000201:enzymology / Q000378:metabolism*; D014238:Trichloroacetic Acid
D011756:Diphosphates; D010710:Phosphates; D010761:Phosphorus Radioisotopes; D014238:Trichloroacetic Acid; C006226:4-bromotetramisole; D013773:Tetramisole; D000469:Alkaline Phosphatase