Медицина/ 8. Морфология

Ph.D. Kutya S.A.

Crimea State Medical University named after S.I. Georgievskiy, Ukraine

Hypergravity affects bone turnover of vertebrae of various age rats

INTRODUCTION. The aim of this study was to reveal the effect of chronic hypergravity (HG) exposure on the bone turnover in rat vertebra.

METHODS. We used fourth lumbar vertebrae from male Wistar rats (2, 6, 12 months of age) subjected to HG (9g, 10 minutes, daily, 60 times). The physical properties (apparent density (ρ_a), bone mineral content (BMC) and apparent ash density (ρ_s)) of the specimens were determined. Density was measured by Archimedes' technique. Ca, P, Mg and Na content in bone was determined biochemically. Features measured by histomorphometry were: cancellous bone volume/tissue volume (Cn-BV/TV), cortical width (Ct.Wi). Bone robusticity was calculated using the ponderal index: P.I. = bone length divided by 3 square root bone weight.

RESULTS. HG increased ρ_a, ρ_s, Na content, Cn-BV/TV and decreased Mg content in 2 month-old rats. Other studied parameters were not statistically significantly affected. HG insignificantly decreased ρ_a, increased Ca and P content. The histomorphometry revealed that Cn-BV/TV was significantly decreased, whereas Ct.Wi increased compared to control rats. P.I. of HG subjected rats was lower than in the control group by 3,26% (p<0,05). Compared with controls, HG subjected 12 month-old rats had alterations similar to previous age group.

CONCLUSION. These data indicate that HG stimulates bone formation in 2 month-old rats and does not affect bone robusticity. While HG inhibits both bone formation and resorbtion (more affected) in 6 and 12 month-old rats, insignificantly reduces bone robusticity.