Bone maturation and quality of bone material in rats flown on the space shuttle 'Spacelab-3 Mission'

The maturation profiles of calcium, phosphorus, magnesium and hydroxyproline in the femoral trabecular and cortical bone and in the thoracic vertebrae from male rats flown on the 7-day 'Spacelab-3 Mission' were measured by density gradient analysis. In rats exposed to a spaceflight environment, profiles of the matrix and mineral moieties were shifted toward both the lower (vertebrae) and higher density fractions (femurs and vertebrae), patterns indicating a decrease in bone growth/turnover. X-Ray diffraction of vertebrae indicated that spaceflight is associated with a decrease in apatite crystal size/perfection.