Changes in chromatin and nucleic acids in rat tissues after two-week spaceflight.
The quantitative changes in nucleic acids and chromatin breakdown were followed in blood, thymus and spleen in rats after 14 day flights on board the biosatellites Cosmos-1887 and Cosmos-2044. Quantitative nucleic acid changes within 8-11 h after landing were only mild, most statistically non-significant. An analysis at 48 h after landing showed a marked decrease in a total content of DNA and RNA in spleen and thymus. Within 8-11 h after landing, the symptoms of chromatin breakdown were found as is seen in an increased concentration of its fragments-polydeoxyribonucleotides. The obtained results show that a partial adaptation to microgravity occurs up to flight day 14 in lymphoid organs. Adaptation is accompanied with a reappearing of the sensitive cells. Their chromatin breaks down, then, in a final phase of flight due to hypergravity stress manifesting itself by a temporary increase in polydeoxyribonucleotide concentration several hours after landing. The results are discussed in relation to the changes in chosen parameters after shorter or more prolonged flights.
Misurova
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Institute of General Biology, P.J. Safarik University, Kosice, Czechoslovakia.
Kropacova
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K
D000222:Adaptation, Physiological; D000818:Animals; D002843:Chromatin / Q000737:chemistry* / Q000378:metabolism; D004247:DNA / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D011089:Polydeoxyribonucleotides / Q000032:analysis / Q000378:metabolism; D012313:RNA / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013026:Space Flight; D013154:Spleen / Q000737:chemistry / Q000378:metabolism; D013950:Thymus Gland / Q000737:chemistry / Q000378:metabolism; D014893:Weightlessness
D002843:Chromatin; D011089:Polydeoxyribonucleotides; D012313:RNA; D004247:DNA