[Results of the studies on radiation ecology and radiation biology at the Institute of Biology of Komi Science Center of Ural division of Russian Academy of Science (on 40th anniversary of the Department of Radiation Ecology)]. / Itogi issledovanii po radioékologii i radiobiologii v Institute Biologii Komi Nauchnogo tsentra Ural'skogo otdeleniia Rossiiskoi akademii nauk (k 40-letiiu otdela radioékologii).

Information about the foundation and history of the Radiation Ecology Department and results of the researches on the effect of increased background radiation level on plant and animal populations, migration of radionuclides in natural biocoenosies with increased radiation level are presented.

[Histomorphological study of mice inbred CBA liver under combined chronic influence of low dose gamma radiation and incorporated thorium nitrate]. / Gistomorfologiia pecheni myshei linii CBA pri kombinirovannom khronicheskom deistvii gamma-izlucheniia maloi moshchnosti i inkorporirovannogo nitrata toriia.

We studied histomorphology of the CBA line mice liver after 30 and 90 days of the low dose gamma-radiation influence combined with incorporated Th(NO3)4 in doses 0.03; 0.1; 0.3 grams per kilogram of the living mouse weight. Morphophysiological and morphometric changes were shown. The liver mass and index were significant by increased after 30 days influence. The same changes after 90 days influence were not shown. The morphometric parameters (dynamics of double-nucleus and polyploid hepatocytes, nucleoluses numbers) gave evidence of the liver energy disbalance.

[The structural-functional disorders in the liver of wild rodents from areas of the accident at the Chernobyl Atomic Electric Power Station]. / Strukturno-funktsional'nye narusheniia v pecheni dikikh gryzunov iz raionov avarii na Chernobyl'skoi AES.

A study was made of the morphological status of hepatocytes, the antioxidant activity of lipids and composition of phospholipids, and dehydrogenase activity in the liver of field mice taken from seven regions of the Chernobyl A.P.S. zone with different levels of contamination in 1987. There observed multiple types of destructive damages to the organ; depletion of liver lipids by antioxidants; diminution of phospholipids within the total lipid level; considerable increase in the phosphatidyl choline/phosphatidyl ethanolamine ratio and in the relative content of phospholipid lysoforms; and inhibition of dehydration processes. In the absence of a strict correlation between the changes in the biophysical and biochemical parameters or between the severity of degenerative changes in hepatocytes and the level of external irradiation, certain relationship was followed up between liver lipid depletion by antioxidants, inhibition of dehydration processes and the number of wild rodents which developed dystrophic changes in the organ. These structural and functional changes were found in the liver of wild rodents taken from all the regions: this indicated a considerable sensitivity of the parameters of the regulatory cell systems and hepatocytes to the effect of technogenic contamination.

[Effect of an increased level of natural radioactivity on the glycogen content of peripheral blood leukocytes in Microtus oeconomus Pall]. / Vliianie povyshennogo urovniia estestvennoi radioaktivnosti na soderzhanie glikogena v leikotsitakh perifericheskoi krovi polevok-ekonomok (Microtus oeconomus Pall.).

In experiments on Microtus oeconomus Pall., living in natural conditions with normal (0.72-1.08 pA/kg) and increased (3.6-1440 pA/kg) levels of external gamma-irradiation and affected by numerous incorporated radionuclides, the differences were detected, by the cytochemical method, both in the total glycogen content of leucocytes and in the type of grouping of cells depending on the degree of their saturation with polysaccharide.

[Action of chronic gamma irradiation on chipmunks in a vivarium]. / Deistvie khronicheskogo gamma-oblucheniia na burundukov v usloviiakh vivariia.

The activity, the dynamics of changes in the body mass and the weight of some internal organs of chipmunks at different physiological status were studied in normal conditions (0.86 pA/kg) and during chronic gamma-irradiation at low dose-rates (46.3 pA/kg). The stated higher indications of body mass and the lower activity of the animals from the experimental group during the hibernation period can be regarded as the favourable protective reaction of the organism to the chronic effects of gamma-irradiation with low doses.

[Effect of increased natural radioactivity on bone marrow morphology of Microtus oeconomus pall]. / Vliianie povyshennoi estestvennoi radioaktivnosti v srede obitaniia na morfologiiu kostnogo mozga u Microtus oeconomus pall.

It was established that Microtus oeconomus Pall. living in territories with the increased radiation background exhibit focal myeloid hyperplasia in the bone marrow, changes in the maturation indices of erythroid and myeloid elements, increase in number of karyocytes due to the increase in their mitotic activity. It is suggested that activation of vole haemopoiesis is an adaptive reaction of the organism to the effect of the radioecological factor.