acid-phosphatase and fluorophosphate

Topics: Acid Phosphatase; Alkaline Phosphatase; Chemical Phenomena; Chemistry; Fluorides; Hydrolysis; Phosphates; Phosphotransferases

These studies were intended to assess the osteogenic activity of monofluorophosphate (MFP) in vitro, and to identify the enzyme(s) responsible for MFP hydrolysis-alkaline phosphatase (ALP) and/or acid phosphatase (AcP). ALP and AcP activities were determined by hydrolysis of p-nitrophenylphosphate (PNPP) at pH greater than 8 and pH 5.5, respectively, and MFP hydrolysis was determined, between pH 5.5 and pH 9.0, from measurements of [fluoride ion], using an ion-specific electrode. We found (1) that MFP was an alternative substrate for purified ALP, but not for AcP; (2) that MFPase activity in the embryonic chick resembled ALP, but not AcP, with respect to pH-dependent hydrolysis, sensitivity to effectors (r = 0.98, P less than .001), and tissue distribution (r = 0.96, P less than .001); and (3) that intestinal MFPase activity in the embryonic chick co-purified with ALP activity (r = 0.93, P less than .01) and resembled ALP, but not AcP, in its distribution along the small intestine, being highest in the duodenum and lowest in the distal ileum (r = 0.96, P less than .001). We also found that in vitro exposure to MFP increased (1) the proliferation rate of embryonic chick calvarial cells in serum-free monolayer cultures (i.e., 3[H]-thymidine incorporation into DNA, P less than .001); (2) ALP activity in calvarial cells (P less than .005) and in intact calvaria (P less than .05); and (3) collagen production by intact calvaria (i.e., 3[H]-proline incorporation as 3[H]-hydroxyproline, P less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Bone and Bones; Cell Division; Cells, Cultured; Chick Embryo; Collagen; Fluorides; Humans; Hydrogen-Ion Concentration; Intestine, Small; Phosphates; Sodium Fluoride

When a bleached strain of Euglena is maintained in a medium containing very low con centrations of phosphate, the acid phosphatase activity increases. The increase in acid phosphatase activity is prevented by Actinomycin D and by p-fluorophenylalanine (PFA), indicating that the increased activity is due to de novo synthesis of acid phosphatase. When phosphate is replenished, the acid phosphatase activity decreases to the level characteristic of uninduced cells before there is any appreciable cell division. When cell division resumes in the presence of PFA, the level of acid phosphatase activity remains approximately constant. This indicates that there are two different phosphatases: a constitutive enzyme, whose synthesis is insensitive to the presence of PFA, and an induced enzyme, whose synthesis is sensitive to PFA. These enzymes are not equally sensitive to changes in pH and in fluoride concentration, thus permitting them to be assayed individually in whole toluene-treated cells. Induced cells also acquire the ability to remove phosphate from the medium very rapidly.

Topics: Acid Phosphatase; Cell Division; Centrifugation; Culture Media; Dactinomycin; Dinitrophenols; Electrons; Euglena; Euglena gracilis; Fluorides; Hot Temperature; Hydrogen-Ion Concentration; Metabolism; Microscopy; Microscopy, Electron; Pharmacology; Phosphates; Research; Tartrates

Topics: Acid Phosphatase; Alanine Transaminase; Alkaline Phosphatase; Aspartate Aminotransferases; Bone and Bones; D-Alanine Transaminase; Diet; Fluorides; Growth; Heart; Isocitrate Dehydrogenase; Kidney; L-Lactate Dehydrogenase; Liver; Metabolism; Phosphates; Rats; Research; Transferases

Topics: Acid Phosphatase; Fluorides; Humans; Hydro-Lyases; Male; Phosphates; Phosphopyruvate Hydratase; Phosphoric Monoester Hydrolases; Prostate; Protein Tyrosine Phosphatases; Salivary Glands; Yeast, Dried

Topics: Acid Phosphatase; Duodenum; Fluorides; Phosphates; Phosphoric Monoester Hydrolases

Topics: Acid Phosphatase; Fluorides; Hot Temperature; Phosphates; Phosphoric Monoester Hydrolases; Protein Tyrosine Phosphatases

Topics: Acid Phosphatase; Fluorides; Humans; Male; Phosphates; Phosphoric Monoester Hydrolases; Prostate; Protein Tyrosine Phosphatases