Spaceflight Stress Linked to DNA Breakdown in Rat Spleen and Thymus

Misurova and colleagues, writing in Advances in Space Research in 1981, studied how spaceflight affects the packaging of DNA with protein, called deoxyribonucleoprotein, inside rat organs. This is a basic physiology study, not a skincare or wound-healing study, and it does not involve any applied or therapeutic use of DNA fragments.

Rats flew aboard the Cosmos 782 and Cosmos 936 biosatellites for 20 days, either in weightlessness or under artificial gravity created onboard. After landing, the researchers measured deoxyribonucleoprotein and its breakdown products, called polydeoxyribonucleotides, in the spleen, thymus and liver. In animals that had experienced weightlessness, polydeoxyribonucleotide levels rose 4 to 11 hours after landing in the spleen and thymus, which the authors interpret as partial breakdown of deoxyribonucleoprotein, alongside falling deoxyribonucleoprotein content. Artificial gravity blocked this effect in the thymus but not the spleen. No real change appeared in the liver. Over a 25-day recovery period, values mostly returned to normal. The authors attribute the breakdown to a nonspecific stress response triggered by the sudden return to Earth's gravity, and link organ differences to cell types prone to a specific kind of nuclear shrinkage, called pycnosis, in the spleen and thymus but not the liver.

As an abstract-only report from 1981, the study gives no information on dose, fragment size, or mechanism beyond this description, and cannot tell us anything about DNA fragments used as an external compound or ingredient.