[Mineral phase and protein matrix status of rat bony tissue after a flight on the Kosmos-1129 biosatellite]. / Sostoianie mineral'noi fazy i belkovogo matriksa kostnoi tkani krys posle poleta na biosputnike "Kosmos-1129".

The major parameters of the mineral component and protein matrix of bones were investigated in 30 rats flown onboard Cosmos-1129. Postflight, the content of calcium decreased by 7.8%, that of phosphorus diminished by 11.8%, the Ca/P ratio increased by 5.9%, the content of collagen diminished by 14.7% and that of non-collagenous proteins by 45.7% and the content of sialic and hexuronic acids increased by 36.2% and 14.6%, respectively, as compared to the vivarium controls. The paper discusses the role of EDTA-and HCl-protein extracts, soluble and poorly soluble calcium fractions, protein-Ca-phosphate complex, sialic and hexuronic acids in the mechanism of calcium binding by the bone organic matrix.

[Comparative study of the effect of weightlessness and artificial gravity on the density, ash, calcium, and phosphorus content of calcified tissues]. / Sravnitel'noe izuchenie vliianiia nevesemosti i iskusstvennoi sily tiazhesti na plotnost' soderzhanie zoly, kal'tsiia i fosfora v obyzvestvlennykh tkaniakh.

The studies were carried out on 30 rats flow for about 19 days aboard the biosatellite Cosmos-936 (5 centrifuged rats including) and 25 ground-based control rats. Postflight the centrifuged rats did not show significant differences in the density, mineral saturation, distribution of vascular channels in bones, ash, calcium and phosphorus content in skeletal bones and teeth as compared with the parameters in synchronous and vivarium controls. In the weightless rats these values were significantly lowered.