title: Effect of microgravity on collagenase deproteinization and EDTA decalcification of bone fragments.
abstract: Undecalcified (n = 140) and decalcified (n = 11) bone fragments were treated with either collagenase (to remove collagen portion; undecalcified n = 64, decalcified n = 11) or EDTA (to remove mineral portion; n = 76) under the reduced gravity environment on US Space Shuttle mission STS-57. The fragments were initially stored in Dulbecco's phosphate buffer solution. After orbit had been established, fragments were exposed to either a neutral buffered collagenase or EDTA solution. Reactions were terminated (neutral buffered formalin for collagenase, 21% CuSO4 5H2O for EDTA) before reentry to earth's atmosphere. Differences in bone samples mass from before flight to after flight were measured. EDTA-treated sample mass was corrected for CuSO4 content. Flight and matched ground (gravitational control) sample showed similar EDTA-induced loss of mineral mass. Collagenase treatments, however, appeared to be more effective in flight samples compared to ground control samples. The flight-exposed, collagenase-treated samples showed significantly more loss of mass than did ground samples. The microgravity environment appeared to promote proteolytic reactions in bone more than the EDTA decalcification reaction.
authors.affiliation: Bioserve Space Technologies, Department of Aerospace Engineering Sciences, University of Colorado, Boulder 80309, USA.
authors.forename: S J
authors.initials: SJ
authors.lastname: Simske
authors.forename: M W
authors.initials: MW
authors.lastname: Luttges
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D001842:Bone and Bones / Q000737:chemistry / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology*; D017364:Collagenases / Q000378:metabolism / Q000494:pharmacology*; D019327:Copper Sulfate / Q000032:analysis / Q000494:pharmacology; D003648:Decalcification Technique; D004492:Edetic Acid / Q000494:pharmacology*; D005110:Extracellular Space; D005269:Femur; D005404:Fixatives / Q000494:pharmacology; D005557:Formaldehyde / Q000032:analysis / Q000494:pharmacology; D006811:Humerus; D051379:Mice; D013026:Space Flight; D013977:Tibia; D014893:Weightlessness
chemical_list: D002614:Chelating Agents; D005404:Fixatives; D005557:Formaldehyde; D004492:Edetic Acid; D017364:Collagenases; D019327:Copper Sulfate