[The alterations in profiles of RAPD- and of ISSR-markers in progeny of the single gamma-irradiated mice of BALB/c strain].

Molecular-genetic effects in the offspring of BALB/c male mice exposed to single radiation doses of 1, 2 and 3 Gy were studied. Induced genetic variability was studied using such methods as assessment of variation RAPD- and ISSR-profiles. Comparative analysis of genetic radiosensitivity of stem spermatogonia and of spermatids is presented in the work. The frequency of changes in the patterns of the offsprings of irradiated mice was significantly different from the analogous parameters in the offsprings of the control group already at a dose of 1 Gy. Comparative analysis of genetic radiosensitivity at different stages of spermatogenesis revealed the similar sensitivity of spermatogonia and of spermatids at 1 and 3 Gy and a higer sensitivity of spematogonia at 2 Gy.

[Genetic consequences of an increased radiation background at mouse-like rodents].

The frequency of genetic disturbances in germ-line and in somatic cells was studied in animals caught in radionuclide-cotaminated areas within the 30-km Chernobyl NPP zone as well as in model experiments in laboratory mice exposed to chronic external gamma-radiation or to the internal action of incorporated radionuclides (131I, 137Cs, 238Pu). The results of genetic and of cytologic analysis of germ-line and somatic cells in the caught or exposed house mice and in laboratory mice after incorporation of radionuclides are presented. An estimation of relative genetic efficiency of the most harmful radionuclides was made.

[The influence of chronic and of acute irradiation on the polymorphism of RAPD-markers in offspring for irradiated mice].

On mice lines BALB/c and CBA/lac was performed the study of molecular-genetics effects in mice progeny after the chronic (dose rate -0.0017 Gy/day, total dose -0.36 Gy) and acute (dose range 1-3 Gy) exposure of y-radiation on the parents. For variability analysis was used technique of amplification DNA with series of random primers (RAPD-assay). Random primers were used as single primer and in mixture of ones. In this work were held the comparative analysis of the genetic radiosensitivity for stem spermatogonia and spermatides. After the acute exposure the dose dependence for levels of polymorphism of RAPD-markers were obtained. After the chronic irradiation, significant differences from control group were obtained only by use primers mixture M1. Comparative analysis of the genetic radiosensitivity of different stages of mice spermatogenesis are display is similar sensitivity of stem spermatogonia and spermatides after doses of irradiation 1 Gy and 3 Gy. Indicated that after irradiation by dose 2 Gy, spermatogonia are more sensitivity than spermatides.

[Effects of para-aminobenzoic acid on radiosensitivity of mice of different strains]. / Vliianie paraaminobenzoinoi kisloty na radiochuvstvitel'nost' myshei raznykh linii.

The aim of the work was to study the possible protective effect of para-aminobenzoic acid (PABA) on the radiation lethality in mice of three inbred lines (BALB/cLacY, C3H/HeY, 101/Hy), stock YT1 and hybrids (C3H/He x 101/H)F1. The PABA solution was given to the mice intraperitoneally in single doses of 10, 50 and 100 mg/kg 40-50 min prior to irradiation with doses of 6 to 8 Gy depending on the line and sex of mice. The used doses of gamma-radiation were roughly LD75/30. The radioprotective effect of PABA was observed in all variants of the experiment but it was relatively low. The protection coefficient varied from 0 to 0.45. The protective effect depended on the line and sex of mice and on the dose of the injected substance.

[Mutagenesis in Muridae from regions with increased radiation level]. / Mutatsionnyi protsess u myshevidnykh gryzunov, obitaiushchikh v raionakh s povyshennym fonom radiatsii.

Genetic monitoring of wild populations of mouse-like rodents has been carried out since 1992 in areas with the increased radioactivity in the south of the Bryansk region. The radioactive background ranged from 0.20 to 2.20 mkGy/h. Over 400 rodents of different species have been examined. Bank vole constituted more than a half of the examined animals. The genetic effect of radiation was estimated by the frequency of micronuclei in normochromatic erythrocytes of peripheral blood and by the frequency of abnormal sperm heads. In house mice the frequency of reciprocal translocations and the level of embryo mortality were studied in the progeny of the caught male mice mated with intact laboratory females. The data obtained demonstrate that the yield of induced genetic disorders by all tests was relatively low and only in a few cases the frequency of disturbances tended to increase with an increase in the level of radionuclide contamination in the examined areas.

[Modification of the genetic effect of radiation in mice exposed in the region of the Chernobyl Atomic Electric Power Station]. / Modifikatsiia geneticheskogo éffekta radiatsii u myshei, éksponirovannykh v raione Chernobyl'skoi AES.

A study was made of the protective effect of beta-carotine and ephasol against genetic damages in germ cells of male mice, exposed within the zone of Chernobyl NPP or ingested by 137Cs. The analysis of reproductive function, frequencies of dominant lethal mutations, abnormal sperm heads, reciprocal translocations and testis mass decrease show that both agents are more effective in protection against reproductive function damages than against genetic effects.

[The radioprotective action of efazol under different conditions of irradiation of the germ cells of male mice]. / Radiozashchitnoe deistvie éfazola pri raznykh usloviiakh oblucheniia polovykh samtsov myshei.

A study was made of the protective effect of ephasol against genetic damages induced in mice germ cells by single, fractionated and chronic gamma radiation. Study of male reproductive ability, frequency of induced dominant lethal mutations, abnormal sperm heads and reciprocal translocation show that the efficacy of ephasol was higher in condition of chronic exposure.

[The effect of chronic exposure to cadmium and gamma radiation at low doses on the genetic structures in mice]. / Vliianie khronicheskogo vozdeistviia kadmiia i gamma-izlucheniia v malykh dozakh na geneticheskie struktury myshei.

The DNA-protein cross-links (DPC) in mouse thymocytes and spleen lymphocytes, the number of abnormal sperm heads (ASH) and the number of micronuclei (MN) in normochromatic erythrocytes (NCE) of peripheral blood were studied in mice exposed to long-term low-intensity gamma radiation (0.072 cGy/days) and/or cadmium with drinking water (0.01 mg Cd2+/l) for 20, 40 and 80 days. The dependence of DPC level on the total dose (exposure time) of gamma radiation and/or cadmium is nonlinear. The maximal level of DPC in cells of lymphoid organs upon exposure to gamma radiation or cadmium was recorded on the 40-th day, and under combined exposure on the 20-th day of the experiment. The long-term exposure to cadmium or gamma radiation causes an increase in the ASH frequency. The increase in frequencies of MN in NCE and reciprocal translocations in spermatocytes was not found.

[Genetic effect of incorporated 137 Cs in male mice after single injection of the isotope]. / Geneticheskii éffect inkorporirovannogo 137 Cs u samtsov myshei pri odnokratnom vvedenii izotopa.

A comparative study of the incidence of genetic damages induced in mouse male germ cells by a single injection of 137Cs and external gamma-irradiation shows that the incidence of dominant lethal mutations in the postmeiotic cells is similar with both radiation types. The frequency of reciprocal translocations in stem cell spermatogonia was considerably lower with 137Cs than with external gamma-irradiation which might be attributed to the prolonged effect of the radionuclide.

[Genetic effect of incorporated 137 Cs on male mice after long-term administration of the isotope]. / Geneticheskii éffect inkorporirovannogo 137 Cs u samtsov myshei pri dlitelnom vvedenii izotopa.

A comparative study has been made of the incidence of genetic damages to male mouse germ cells induced by chronic action of incorporated 137Cs and external gamma-radiation. It has been shown that the genetic efficiency was nearly the same with both radiation types under conditions of equal, with respect to time and value, absorbed dose formation in gonads.

[Estimation of genetic effects of chronic exposure to low-dose rate gamma-radiation by cytogenetic methods and DNA-comet assay]. / Otsenka geneticheskikh éffektov khronicheskogo vozdeistviia nizkointensivnogo gamma-izlucheniia tsitogeneticheskimi metodami i metodom DNK-komet.

The study of genetic effects in CBA/lac mice exposed for 1 year to constant low dose-rate gamma-radiation at a dose-rate 63 cGy/year has been carried out. We have shown the significant increase in the DNA breaks' level in spleen lymphocytes by comet-assay beginning from the total absorbed dose of 20 cGy. It is possible that the DNA breaks' level increase resulted from the structural rearrangement of chromatin or induction of lymphocyte proliferation. The results obtained by micronucleus test have proved that the mutagenic effect of chronic low dose-rate gamma-radiation depends on cell type and respectively on cell proliferation rate, cell differentiation, etc. So, by the end of experiment the significant increase in the frequency of PCE with micronuclei (MN) was observed. However, in contrast, the frequency of NCE with MN was not increased. No significant increase in the percent of lung cells with MN was registered.

[Mutagenic action of cadmium on the sex cells of male mice]. / Izuchenie muragennogo deistviia kadmiia na polovye kletki samtsov myshei.

Possible mutagenic effect of cadmium chloride was studied by determining the frequency of dominant lethal mutations induced in germ cells of male mice. Water solution of CdCl2 was injected intraperitoneally to male mice at doses of 1.0, 2.0 and 4.0 mg/kg. The results obtained did not reveal any mutagenic effect of this compound. The dose of 4.0 mg/kg CdCl2 resulted in the death of spermatocytes and spermatogonia and the sterility of male mice. Cadmium chloride at a dose of 2.0 mg/kg did not affect the frequency of dominant lethal mutation induced by gamma-rays 60Co at a dose of 450 r in germ cells of male mice.

[Comparative effectiveness of different tests to determine the mutagenicity of certain factors in mammals. II. Frequency of anomalous sperm head in mice exposed to different factors]. / Sravnitel'naia éffektivnost' ispol'zovaniia raznykh testov dlia opredeleniia mutagennosti nekotorykh faktorov u mlekopitaiushchikh. Soobshchenie II. Chastota anomal'nykh golovok spermiev u myshei, podvergshikhsia vozdeistviiu razlichnykh faktorov.

The effect of a number of chemical and physical agents (cyclophosphamide (CTX) - 50, 100 and 300 mg/kg; N-nitroso-N-methylurea (NMU) - 50 mg/kg; N-nitrosomorpholine (NM) - 50 and 150 mg/kg; CdCl2 - 1, 2 and 4 mg/kg; ZnCl2 - 15 mg/kg; microwaves and gamma-rays 60Co on the frequency of abnormal sperm heads (ASH) in mouse F1 hybrids (C57BL X CBA) was studied. The agents possessing mutagenicity in the dominant lethal mutations (DLM) and bone marrow chromosome aberrations assay (CTX, NMU and gamma-rays) significantly increased the ASH frequency within 35 days after the treatment at maximum doses. CdCl2 inducing no mutagenic effect in the DLM test, increased the ASH frequency too. The increase in the ASH frequency all cases was accompanied by a reduction of the testicular weight and an increase in preimplantation losses and a reduction of the level of efficient matings when premeiotic germ cells were treated. This indicates that the occurrence of ASH may be due not only to the mutagenic but also cytolytic or/and cytotoxic effects of the compounds. The ASH test can be used for mutagenicity prescreening of different factors provided their doses are high enough.

[Comparative effectiveness of using different tests to determine the mutagenicity of certain factors in mammals. I. Frequency of dominant lethal mutations and chromosome aberrations in mouse bone marrow cells induced by N-nitrosomorpholine, N-nitroso-N-methylurea and cyclophosphamide]. / Sravnitel'naia éffektivnost' ispol'zovaniia raznykh testov dlia opredeleniia mutagennosti nekotorykh faktorov u mlekopitaiushchikh. Soobshchenie I. Chastota dominantnykh letal'nykh mutatsii i khromosomnykh aberratsii v kletkakh kostnogo mozga myshi, indutsirovannykh N-nitrozomorfolinom, N-nitrozo-N-metilmichevinoi i tsiklofosfamidom.

Two tests (the frequency of dominant lethal mutations at different stages of spermatogenesis and the yield of chromosome aberrations in bone marrow cells) were used to investigate mutagenisity of N-nitrosomorpholine (NM), N-nitroso-N-methylurea (NMU) and cyclophosphamide (CTX). The drugs were injected once intraperitoneally to male mice (F1 of CBA X C57BL) at doses of NM--50 mg/kg; NMU--50 mg/kg; CTX--50, 100, 200 and 300 mg/kg. It was established that NM was not mutagenic in the mouse as measured by these two tests. NMU was a weak mutagen at the stated exposure, since there was only slight increase in the frequency of dominant lethal mutations in late spermatids and spermatogonia, and also a low yield of chromosome aberrations in bone marrow cells was induced. CTX had a strong mutagenic effect on postmeiotic stages of spermatogenesis and in bone marrow cells.

[Absence of a mutagenic effect of cadmium and zinc salts in mouse somatic and sex cells]. / Otsutstvie mutagennogo éffekta solei kadmiia i tsinka v somaticheskikh i polovykh kletkakh myshi.

Mutagenic effect of cadmium chloride and zinc chloride on the yield of chromosome aberrations induced in bone marrow cells and the frequency of dominant lethal mutations induced by zinc chloride in male germ mouse cells are studied. Water solutions of CdCl2 and ZnCl2 were injected intraperitoneally to male mice at doses of 4 and 15 mg/kg respectively. The results obtained did not reveal any mutagenic effect of these salts in somatic cells and of ZnCl2 in germ cells of mice.

[Mutagenic effect of different types of irradiation on the sex cells of male mice. X. Frequency of recessive lethal mutations and reciprocal translocations in the spermatogonia of mice subjected to fractional gamma-irradiation]. / Mutagennyi éffekt izluchenii raznykh vidov v polovykh kletkakh samtsov myshei. Soobshchenie X. Chastota retsessivnykh letal'nykh mutatsii i retsiproknykh translokatsii v spermatogoniiakh myshei, podvergshikhsia fraktsionirovannomu gamma-oblucheniiu

The frequency of recessive lethal mutations and reciprocal translocations was investigated in spermatogonia of CBA male mice which were thrice gamma-irradiated at doses of 300 r with 28 days intervals. The rate of induced recessive lethals was estimated 1) by comparison of embryos survival between the irradiated and control groups in mating of the F1 males with their daughters, and 2) by estimation the frequency of males heterozygotes for recessive lethals in the first generation. In the first case the frequency of recessive lethals was 2,8 +/- 0,8-10(-4) per r per gamete (for the pre- and post-implantation death) and 1,6 +/- 0,1-10(-4) per r per gamete (for the pre- and post-implantation death) and 1,6 +/- 0,1-10(-4) per r per gamete in the second case. The frequency of heterozygotes for reciprocal translocations in the first generations of males was 3,1 +/- 0,9-10(-5) per r per gamete.

[Evaluation of genetic consequences of 238Pu incorporation into mammals]. / Otsenka geneticheskikh posledstvii postupleniia 238Pu v organizm mlekopitaiushchikh.

The genetic effects of gonadal burdens of 238Pu after single injection were studied in male mice. The activity of plutonium was 7 to 1850 Bk/g. The average doses of accumulated alpha-particles in testis varied from 2 to 96 Gy.10(-2), the dose rate being 0.004 to 1 Gy.10(-2) per day. The genetic end points are: the dominant lethal mutation rate; the frequency of reciprocal translocations; the recessive lethal mutation rate and frequency of abnormal sperm head morphology. For all tests used, no linear dependence of the effect on the alpha-dose was observed. The RBE value of alpha-irradiation was 10-20 relative to chronic gamma-irradiation.

[Mutagenic action of tritium on the germ cells of male mice. II. The genetic damages in stem spermatogonia induced by tritium oxide and gamma radiation]. / Mutagennoe diestvie tritiia na polovye kletki samtsov myshi. Soobshchenie II. Geneticheskie povrezhdeniia v stvolovykh spermatogoniiakh, indutsirovannye okis'iu tritiia i gamma-izlucheniem.

The frequency of reciprocal translocations (RT) induced by single injection of tritiated water (THO) (3.3; 6.3 and 12.6 MBq/g) or by referent 137Cs gamma irradiation was studied. The absorbed doses in testis were: 1; 2 and 4 Gr. The frequency of RT per 100 cells were 0.4; 1.1 and 2.5 after THO administration, and 0,5; 0.9 and 1.2 after single exposure to gamma irradiation, respectively. The RBE of tritium increased from 1 at the dose of 1 Gr to 2, at the dose of 4 Gr.

[Comparison of three inbred lines of mice by overall and genetic radiosensitivity]. / Sravnenie trekh inbrednykh linii myshei po obshchei i geneticheskoi radiochuvstvitel'nosti.

The radiosensitivities of three mouse strains (BALB/cLacY, C3H/SnY, and 101/HY) have been compared using the following parameters: survival after irradiation at a dose of 6-7 Gy, chromosome aberration frequency in bone marrow cells after irradiation at a dose of 1.5 Gy, and the change in testis weight and frequency of abnormal sperm heads (ASHs) after irradiation at doses from 0.5 to 4 Gy. Strain BALB/c is the most radiosensitive with respect to the survival and chromosome aberration frequency in the bone marrow but the most resistant with respect to the change in testis weight and the frequency of abnormal sperm heads. Strain 101/HY was the most resistant with respect to survival and chromosome aberration frequency in bone marrow after irradiation but the most radiosensitive with respect to testis damage.

[Effect of indralin on genetic disruption induced by radiation in mice]. / Vliianie indralina na geneticheskie narusheniia, indutsirovannye radiatsiei u myshei.

The effect of indralin on frequency of mutations induced by radiation in germ cells, reciprocal translocations, and testicle weight of male mice. The level of protective effect against genetic damage varied depending on the radiation dose and spermatogenesis stage. The values of the defense coefficient ranged from 0.16 to 0.35.