title: Human serum alpha 2HS-glycoprotein modulates in vitro bone resorption.
abstract: We previously isolated a family of bone-resorbing proteins from human cancer ascites fluid and established that the three purified bone-resorbing proteins were chemically and immunochemically related to each other and to alpha-2HS glycoprotein (alpha 2HS). After this finding we purified the normal human serum counterpart of these ascites proteins and studied its effects on bone resorption. The bone-resorbing properties of normal human serum alpha 2HS were examined in vitro over a wide dose range. This normal human serum glycoprotein had a biphasic effect on 45Ca2+ release from bone. More specifically, this protein stimulated bone resorption at the lower concentrations tested, with a maximum effect [treated over control ratio of 2.5 +/- 0.30 (+/- SE); P less than 0.01] at 40 micrograms/mL. In contrast, at doses above 40 micrograms/mL, a sharp decline in calcium mobilization occurred, with a return to baseline occurring above 80 micrograms/mL. These results suggest that serum alpha 2HS may participate in the regulation of bone metabolism in vivo.
authors.affiliation: Department of Biochemistry, Boston University School of Medicine, Massachusettes 02118.
authors.forename: G C
authors.initials: GC
authors.lastname: Colclasure
authors.forename: W S
authors.initials: WS
authors.lastname: Lloyd
authors.forename: M
authors.initials: M
authors.lastname: Lamkin
authors.forename: W
authors.initials: W
authors.lastname: Gonnerman
authors.forename: R F
authors.initials: RF
authors.lastname: Troxler
authors.forename: G D
authors.initials: GD
authors.lastname: Offner
authors.forename: W
authors.initials: W
authors.lastname: Bürgi
authors.forename: K
authors.initials: K
authors.lastname: Schmid
authors.forename: R B
authors.initials: RB
authors.lastname: Nimberg
mesh_terms: D000328:Adult; D000596:Amino Acids / Q000032:analysis; D001202:Ascitic Fluid / Q000032:analysis; D001798:Blood Proteins / Q000032:analysis / Q000494:pharmacology*; D001862:Bone Resorption / Q000187:drug effects*; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D002132:Calcium Radioisotopes; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000032:analysis; D060749:alpha-2-HS-Glycoprotein
chemical_list: C556354:AHSG protein, human; D000596:Amino Acids; D001798:Blood Proteins; D002132:Calcium Radioisotopes; D060749:alpha-2-HS-Glycoprotein; D002118:Calcium