[Changes in the low-molecular fractions of physiologically active substances in the tissues of the spleen, lymph nodes and blood serum of rats exposed to x-ray irradiation].

Acute radiation sickness (grades II-III) was induced in experiments on 135 adult rats by single total X-ray radiation (185.7 mCal/kg). A gel-chromatographic study showed that 40 days after irradiation the surviving animals showed a 2 times increase of substances with a molecular mass of 600-850 daltons in the homogenate of lymphoid organs. This possibly evidences their participation in restorative processes.