[Studies of the radiation-protective effects of indralin on the hematopoietic system of different species of animals]. / Issledovanie radiozashchitnogo éffekta indralina na krovetvornoi sisteme u razlichnykh vidov zhivotnykh.

The experiments were made on mice, guinea pigs and dogs. Radioprotector indraline increased radioresistant state of hematopoietic stem cells in vivo and in vitro, decreased the amount of post-radiation chromosome aberrations in marrow, induced more early and intensive post-radiation proliferative repair of marrow and spleen, faster regeneration of the initial amount of leukocytes, thrombocytes and erythrocytes in blood of mice, guinea pigs and dogs. Antiradiation efficiency of indraline in hematopoietic system is equal to 1.5-2 by FMD. Radioprotective mechanism of indraline effect on hematopoietic system is discussed.

Evaluation of the genetic effects of 238Pu incorporated into mice.

The genetic effects of 238Pu incorporated into male mice were estimated by several tests. The activity of the administered 238Pu nitrate varied from 7 to 1850 Bq/g of body weight. The average alpha-radiation dose absorbed in the testes ranged from 2 to 96 cGy, with a dose rate of 0.004-1 cGy/day. alpha-Radiation from 238Pu was shown to induce dominant lethal mutations (DLM) and reciprocal translocation (RT), chromosomal fragmentation and formation of abnormal sperm heads (ASH). The effect does not depend on the average alpha-radiation dose absorbed in the testis. The relative genetic efficiency of alpha-radiation, as compared with that of chronic alpha-radiation for the indices under study, was about 10-20.

[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.

[Induction of genetic damage by incorporated 238Pu in the germ cells of male mice]. / Induktsiia geneticheskikh povrezhdenii inkorporirovannym 238Pu v polovykh kletkakh samtsov myshi.

Frequency of dominant lethal mutation, occurrence of spermatozoa with abnormal heads, and changes in the testis mass were studied after the administration to mice of 238Pu in doses from 7 to 1850 Bq/g. The frequency of genetic lesions in the testis was not a function of alpha-radiation dose. The rate of the testis mass decrease was a linear function of the dose absorbed. RBE of 238Pu-alpha-radiation, as determined by the incidence of abnormal spermatozoa heads and by the changes in the testis mass, was from 14 to 35 with regard to the chronic effect of gamma-radiation.

[Genetic action of 131I and 125I on the germ cells of male mice]. / Geneticheskoe deistvie 131I i 125I na polovye kletki myshei-samtsov.

A study was made of the genetic effects of iodine radioactive isotopes in male germ cells of (CBA X C57Bl)F1 hybrid mice. After a single intraperitoneal administration of Na131I (1.48 to 740 kBq/g) or Na125I (148 to 7400 kBq/g) to males the occurrence of dominant lethal mutations (DLM), reciprocal translocations (RT), and abnormal sperm heads (ASH) was studied. The radioactive iodine isotopes induced DLM at the postmeiotic spermatogenesis stages only. After the effect of the isotopes, the frequency of RT increased insignificantly with dose. The frequency of ASH was only increased with the highest 131I dose. Relative biological effectiveness of 131I and 125I was less than 1 with a reference to the indices under study.

[Genetic effect of chronic gamma radiation exposure in male mice]. / Geneticheskii éffekt khronicheskogo vozdeistviia gamma-izlucheniia u samtsov myshi.

The frequency of reciprocal translocations (RT) in mouse spermatogonia induced by gamma-rays at doses of 1.5 to 4.5 Gy and dose rates of 2.7 X 10(-6), 5.8 X 10(-6), 9.4 X 10(-5) and 4.5 Gy/min was studied. A linear increase was observed in the RT frequency with increasing the dose, at all dose rates. At 9.4 X 10(-5) Gy/min the RT frequency was, on average, 10 times lower, as compared to that for a single acute dose rate of 4.5 Gy/min. Further reduction of the dose rate did not result in a decrease of the RT yield, and at the lowest dose rate of 2.7 X 10(-6) Gy/min (the dose being 3.0 Gy) the RT frequency was higher than using the same dose at dose rates of 5.8 X 10(-6) and 9.4 X 10(-5) Gy/min. Possible reasons for an increase in the RT frequency at low dose rates are considered. A study of the frequency of abnormal sperm heads (ASH) has shown that at the dose rate of 9.4 X 10(-5) Gy/min it is independent of an accumulated dose and is equal to the value obtained when exposing to an acute dose of 3.0 Gy. At dose rates of 2.7 X 10(-6) and 5.8 X 10(-6) Gy/min ASH frequencies were only slightly increased at all doses, as compared to the control level.

Genetic effect of chronic exposure of male mice to gamma-rays.

The frequency of reciprocal translocations (RT) in mouse spermatogonia induced by gamma-rays at doses of 1.5-4.5 Gy and dose rates of 2.7 X 10(-6), 5.8 X 10(-6), 9.4 X 10(-5) and 4.5 Gy/min was studied. At all dose rates there was a linear increase in the RT frequency with increasing dose. At a dose rate of 9.4 X 10(-5) Gy/min, the RT frequency was on average 10 times lower than that for a single acute dose rate of 4.5 Gy/min. Further dose rate reduction did not result in a decrease in the RT yield, and at the lowest dose rate of 2.7 X 10(-6) Gy/min and a dose of 3.0 Gy the RT frequency was higher than at dose rates of 5.8 X 10(-6) and 9.4 X 10(-5) Gy/min and the same dose. Possible reasons for an increase in the RT frequency at low dose rates are considered. A study of the frequency of occurrence of abnormal sperm heads (ASH) has shown that a dose rate of 9.4 X 10(-5) Gy/min, this frequency is independent of an accumulated dose and is the same as that at an acute dose of 3.0 Gy. At dose rates of 2.7 X 10(-6) and 5.8 X 10(-6) Gy/min, ASH frequencies were only slightly increased at all doses compared to the control level.

[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.

[Genetic effect of 14C incorporated into the male germ cells of mice. Long-term and chronic 14C-glucose administration]. / Geneticheskii éffekt inkorporirovannogo 14C v muzhskikh polovykh kletkakh myshei. Dlitel'noe i khronicheskoe vvedenie 14C-gliukozy.

A study was made of the effect of 14C glucose after long-term (33 days) and chronic (6 and 12 months) per os administration to male mice (CBA X C57B1)F1. The average absorbed doses in gonads were 1.47 and 0.74 Gy after long-term administration and 0.066 and 0.013 Gy after chronic administration of 14C glucose. The tests used were: the frequencies of dominant lethal mutations (DLM), reciprocal translocations (RT), and abnormal sperm heads (ASH). The frequencies of DLM and RT were only shown to increase, with radiation dose, after long-term administration of 14C glucose. After chronic administration, of 14C glucose in the doses applied the effect was absent.

Genetic effects of radiocarbon in reproductive cells of male mice.

The genetic effect of incorporated radiocarbon was studied after single, long-term (33 days) and chronic (6 and 12 months) treatment of male mice (CBA X C57B1) F1 with [14C]glucose. The genetic effect in male germ cells was estimated by 3 tests: DLM frequency in post- and pre-meiotic cells, RT frequency in stem spermatogonia and frequency of abnormal sperm heads. Absorbed doses in the gonads were: 0.22, 0.50 and 1.01 Gy, after a single exposure; 0.74 and 1.47 Gy, after long-term exposures; and 0.006 and 0.031 Gy, after chronic exposure for 6 months; and 0.013 and 0.066 Gy, for 12 months. The results suggest that DLM frequency in post-meiotic cells increased linearly with increasing the dose of 14C single and long-term exposures at a dose of 1.47 Gy only. A chronic treatment with [14C]glucose induced no increase in DLM frequency. RT frequency in stem spermatogonia was statistically significantly higher than the control level after the single and long-term exposure to 14C. A comparison of the results with the results of external single and chronic gamma-irradiation allows the conclusion that the relative genetic efficiency of radiocarbon as compared with that of gamma-rays is about 1.

[Action of UHF microwaves on the germ and somatic cells of mammals]. / Izuchenie deistviia mikrovoln SVCh na polovye i somaticheskie kletki mlekopitaliushchikh.

The mutagenic effect of SHF microwave radiation was studied in male mice using three test: frequency of dominant lethal mutations; frequency of abnormal sperm heads and frequency of chromosome aberrations in cells of bone marrow. The results of acute (60 and 800 mW/cm2 for 12 min, and 21 s., respectively) and fractionated (800 mW/cm2 for 21 s. X 10 days exposures of male mice did not induce any mutagenic effect.

[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.

[Mutagenic effect of different types of radiation on the sex cells of male mice. VIII. Frequency of development of reciprocal translocations in the spermatogonia of mice subjected to chronic gamma radiation]. / Mutagennyi éffekt izluchenii raznykh vidov na polovye kletki samtsov myshi. Soobshchenie VIII. Chastota vozniknoveniia retsiproknykh translokatsii v spermatogoniiakh myshei, podvergshikhsia khronicheskomu gama-oblucheniiu

The frequency of reciprocal translocations in mice spermatogonia after the exposure to chronic gamma-irradiation at doses of 100, 200, 300, 600, 920 r, at the dose rate of 4,2 r/day was investigated. It was shown that the mutation frequency increased insignificantly with the increase of the radiation dose (y=0,8+0,0011x). The comparison of the data obtained with earlier results revealed no changes in the yeild of translocations at the reduction of the dose rate from 10 r/day to 4,2 r/day. The investigation of the genetic radiosensitivity of mice spermatogonia after a chronic gamma-irradiation showed a tendency to increase in their radioresistance.

[The mutagenic effect of different types of irradiation on the sex cells of male mice. VIII. Frequency of development of reciprocal translocations in the spermatogonia of mice subjected to chronic gamma-irradiation]. / Mutagennyi éffekt izluchenii raznykh vidov na polovye kletki samtsov myshi. Soobshchenie VIII. Chastota vozniknoveniia retisiproknykh translokatsii v spermatogoniiakh myshei, podvergshikhsia khronicheskomu gamma-oblucheniiu

The frequency of reciprocal translocations in mice spermatogonia after the exposure to chronic gamma-irradiation at doses of 100, 200, 300, 600, 920 r, at the dose rate of 4,2 r/day was investigated. It was shown that the mutation frequency increased insignificantly with the increase of the radiation dose (y =0,8+0.0011x). The comparison of the data obtained with earlier results revealed no changes in the yield of translocations at the reduction of the dose rate from 10 r/day to 4,2 r/day. The investigation of the genetic radiosensitivity of mice spermatogonia after a chronic gamma-irradiation showed a tendency to increase in their radioresistance.

[Mutagenic effect of irradiating different species on the sex cells of male mice. VIII. Frequency of development of reciprocal translocations in the spermatogonia of mice subjected to chronic gamma-irradiation]. / Mutagennyi éffekt izluchenii raznykh vidov na polovye kletki samtsov myshi. Soobshchenie VIII. Chastota vozniknoveniia retsiproknykh translokatsii v spermatogoniiakh myshei, podvergshikhsia khronicheskomu gamma-oblucheniiu

The frequency of reciprocal translocations in mice spermatogonia after the exposure to chronic gamma-irradiation at doses of 100, 200, 300, 600, 920 r, at the dose rate of 4,2 r/day was investigated. It was shown that the mutation frequency increased insignificantly with the increase of the radiation dose (y = 0,8+0,0011 x). The comparison of the data obtained with earlier results revealed no changes in the yield of translocations at the reduction of the dose rate from 10 r/day to 4,2 r/day. The investigation of the genetic radiosensitivity of mice spermatogonia after a chronic gamma-irradiation showed a tendency to increase in their radioresistance.