Effects of genistein supplemented before or after irradiation on DNA injury in human lymphocytes in vitro.

Background: Ionizing radiation (IR) carry adequate energy to ionize or remove electrons from an atom. Particles interact with water to produce reactive oxygen species (ROS). Genistein (GEN) is a naturally occurring phytoestrogen and the basic isoflavonoid in soybeans and soybean-enriched products and is believed to have the strongest antioxidant activity. Objective: The study aimed at the investigation if application of GEN at different time prior or past irradiation may ameliorate or reduce injury of DNA in human lymphocytes. Material and Methods: The isolated lymphocytes were exposed to X-irradiation (0.5; 1 Gy). GEN (1 µM/ml; 10 µM/ ml) was appended to attempts at various times prior or past irradiation (1 h prior, immediately prior, immediately past, 1 h past). We joined each X-rays dose with each GEN dose. After 1h of incubation DNA damages were examined using Comet assay. Results: Combination of 1 µM/ml of GEN given 1 h before irradiation with low or high dose markedly decreased induced by irradiation DNA injury. Higher dose of GEN applied immediately before or after irradiation markedly extended the frequency of DNA injury generated by irradiation. The result of application 1 µM/ml GEN 1 h after irradiation was not significantly different compared to control. The effect of 1 Gy + 10 µM/ml GEN was not significantly lower compared to each agent alone. Conclusions: Only a very low concentration of GEN applied before irradiation, may be considered as a potential radiomitigator/radioprotector. High doses of GEN work as a radiosentitizer and may potent the effects of radiotherapy.

Radon - occurrence and impact on the health.

Radon is noble, monatomic, radioactive, heavier than the air gas. It is colorless, odorless, tasteless. It exists in natural environment as a result of the decay of radium, and emits mainly alpha radiation and less beta radiation. Residential radon concentrations vary widely by geographic area. The higher concentration of radon is expected globally in the grounds where uranium, radium and thoron are present. Radon may gather in caves, tunnels, mines as well as in other lowestlying spaces, such as basements, and cellars. In accordance with Atomic Law (2000), the reference level for the average annual concentration of radioactive radon in rooms intended for human habitation is 300 Bq/m3. The most dangerous damages caused by ionizing radiation i.e. radon and its derivatives are changes to DNA, which may disturb the functions of cells and in the consequence lead to induction of cancer of respiratory tract, mainly of lungs and also leukaemia. So, the main consequence of exposure to high amount of radon are cancers of respiratory system. Radon enters the human organism mainly through inhaled atmospheric air. Moreover, radon significantly increased a risk of induction cancer in smokers and vice versa, smoking promotes the development of lung cancer after the exposure to radon and its derivatives. Radon may also have beneficial effect on the human body. Therefore it is used in medicine; mainly in radonbalneotherapy i.e. bath treatments, rinsing the mouth and inhalation. Beneficial effects of radon confirms the validity of the theory of radiation hormesis, which assumes that low doses of radiation may stimulate the repair of DNA damage by activation of protective mechanisms, which neutralize free radicals.

The impact of preconceptional exposure of F0 male mice to bisphenol A alone or in combination with X-rays on the intrauterine development of F2 progeny.

Bisphenol A (BPA) is used for the production of polycarbonates and epoxy resins. Exposure to chemical and physical environmental factors may influence the health of exposed individuals, and of the next generations. This paper describes the prenatal effects in the F2 generation of mice after exposure of F0 pubescent or mature males to BPA (5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw), X-rays (0.05 Gy) or a combination of both factors in low doses (0.05 Gy + 5 mg/kg bw BPA) for 8 weeks. F1 males were mated with females from the same group but from a different litter. The females were sacrificed before parturition and examined for the number of implantations, live foetuses, as well as early and late post-implantation deaths. The fertility of males and the percentage of pregnant females in each group were also assessed. Exposure of pubescent F0 males to 10 mg/kg bw of BPA decreased the frequency of fertile males. Following exposure of pubescent males, the frequency of pregnant females decreased in the groups of 10 mg/kg bw and 20 mg/kg bw of BPA, whereas after exposure of adult F0 males in the groups of 5 mg/kg bw and 20 mg/kg bw of BPA, no significant changes in the frequency of total, live and dead implantations in all the experimental groups were found. The results observed in regard to prenatal development of the F2 generation suggest that sperm of the sons of F0 pubescent males exposed to BPA contains genetic defects that affect the possibility of fertilization. The results of both pubescent and mature males exposed to BPA showed that fertilized eggs died before implantation, probably due to defects induced in the sperm. This confirmed that BPA induced transgenerational effects in male germ cells.

Protection and Mitigation by Resveratrol of DNA Damage Induced in Irradiated Human Lymphocytes In Vitro.

The aim of this study was to examine the protective and/or mitigative properties of resveratrol (RSV) administered before or after irradiation of human lymphocytes in vitro. The isolated lymphocytes were incubated for 1 h with resveratrol, at doses of 0.1 (lowest), 0.5 (medium) or 1 (highest) mM/ml: 1 h before; immediately before; immediately after irradiation; and 1 h after irradiation with 0.5, 1 and 2 Gy. The degree of DNA damage was evaluated by Comet Assay. Treatment of human lymphocytes with resveratrol 1 h before or immediately after radiation exposure showed protection from radiation-induced DNA damage. However, 1 Gy irradiation + 1 mM/ml RSV, and 2 Gy irradiation + 0.5 and 1 mM/ml RSV 1 h before irradiation did not provide the same protection. Significant dose-dependent reduction of the level of DNA damage was observed after application of RSV immediately postirradiation or 1 h postirradiation. The reduction in DNA damage was the highest at the 0.1 dose of resveratrol. Our results lead to the conclusion that resveratrol may act both as a radioprotector as well as a radiomitigator. Resveratrol at the lowest (0.5 mM/ml) dose was more effective when combined with 0.5 and 1 Gy doses of radiation.

Amelioration of sperm count and sperm quality by lycopene supplementation in irradiated mice.

Male mice were exposed to lycopene (LYC; 0.15 and 0.30mg kg-1) and irradiation (0.5, 1 Gy) alone or in combination (0.5 Gy+0.15mg kg-1 LYC; 0.5 Gy+0.30mg kg-1 LYC; 1 Gy+0.15mg kg-1 LYC; 1 Gy+0.30mg kg-1 LYC) for 2 weeks. LYC administration in the drinking water was started 24h or on Day 8 after the first irradiation dose or equivalent time point for groups treated with LYC alone. Sperm count, motility, morphology and DNA damage were determined at the end of the 2-week treatment period. Irradiation deteriorated sperm count and quality. Supplementation with LYC from 24h significantly increased the sperm count compared with irradiation alone. In almost all combined treatment groups, the percentage of abnormal spermatozoa was significantly decreased compared with that after irradiation alone. In some cases, combined treatment reduced levels of DNA damage in gametes. Both doses of LYC administered from Day 8 significantly reduced the percentage of morphologically abnormal spermatozoa compared with that seen after 1 Gy irradiation and reduced DNA damage in all combined treatment groups. In conclusion, LYC supplementation after irradiation can ameliorate the harmful effects of irradiation on gametes. Mitigation of radiation-induced damage in germ cells following LYC administration may be useful for radiological accidents and to protect non-treated tissues in patients with cancer undergoing radiotherapy.

The effect of lycopene supplementation on radiation-induced micronuclei in mice reticulocytes in vivo.

Lycopene (LYC) is a natural pigment present in tomatoes and other red fruits and vegetables including red carrots, red peppers, watermelons, pink grapefruits, apricots, pink guavas, and papaya. There is some evidence that LYC may provide protection against mutations induced by ionizing radiation. The study aimed to investigate whether the genetic material of reticulocytes (RET) could be protected from radiation-induced damage by LYC. Mice were treated with LYC [0.15 mg/kg bodyweight (bw), 0.30 mg/kg bw], acute and fractionated irradiation (0.5 Gy, 1 Gy applied daily), or with both agents (0.5 Gy + 0.15 mg/kg bw LYC, 0.5 Gy + 0.30 mg/kg bw LYC, 1 Gy + 0.15 mg/kg bw LYC, 1 Gy + 0.30 mg/kg LYC). LYC supplementation was started at 24 h or 1 week after the first irradiation. Irradiation significantly enhanced the frequency of micronuclei (MN) in RET. LYC treatment at a dose of 0.15 mg/kg bw 24 h after starting fractionated radiation at 1 Gy significantly decreased (41-68%, p < 0.0125) the level of MN in peripheral blood and bone marrow RET. LYC supplementation at 0.30 mg/kg bw did not significantly alter the frequency of MN in peripheral blood, but significantly increased the frequency of bone marrow RET MN. LYC treatment on day 8 following the first radiation exposure showed results similar (92-117%, p > 0.24) to those obtained with irradiation alone. Lycopene may act as a radiomitigator but must be administered at low doses and as soon as possible after irradiation. Contrary, combined exposure with high doses of irradiation and LYC may enhance the mutagenic effect of irradiation.

Reproductive and developmental F1 toxicity following exposure of pubescent F0 male mice to bisphenol A alone and in a combination with X-rays irradiation.

Exposure to environmental toxicants may affect reproduction and development of subsequent generations. This study was aimed at determining the male-mediated F1 effects induced following 8-weeks of subchronic exposure of F0 male mice to bisphenol A (BPA) alone and in a combination with X-rays irradiation (IR) started during their puberty. 4.5 weeks old F0 male mice were exposed to BPA dissolved in ethyl alcohol and diluted in drinking water at the following doses: 5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw or irradiated with X-rays (0.05 Gy) or exposed to a combination of low doses of both agents (0.05 Gy + 5 mg/kg bw BPA). Immediately after the end of the 8 weeks exposure F0 males were caged with two unexposed females each. Three quarters of the mated females from each group were sacrificed 1 day before expected parturition for examination of prenatal development of the offspring. The remainder of the females from each group were allowed to deliver and rear litters. Pups of exposed males were monitored for postnatal development for 8 weeks. At 8-9 weeks of age 6-8 males from each group of F1 generation were sacrificed to determine sperm count and quality. The current results, compared to the earlier results, showed that exposure of pubescent males to BPA alone or in combination with irradiation may be more damaging to their offspring than the exposure of adult males. The exposure of pubescent males to BPA alone and in combination with irradiation significantly increased the frequency of abnormal skeletons of surviving fetuses, increased the percent of mortality of pups in the F1 generation, reduced the sperm motility of F1 males and may induce obesity. Additionally, the combined BPA and irradiation exposure reduced the number of total and live implantations, whereas the exposure to BPA alone disturbed the male:female sex ratio. The above results may be caused by genetic or by epigenetic mechanisms. Limitation of use of products including BPA, especially by children and teenagers, is strongly recommended.

The evaluation of protective effect of lycopene against genotoxic influence of X-irradiation in human blood lymphocytes.

Many studies suggest that exogenous antioxidants may protect cells against DNA damage caused with ionizing radiation. One of the most powerful antioxidants is lycopene (LYC), a carotenoid derived from tomatoes. The aim of this study was to investigate, using the comet assay, whether LYC can act as protectors/modifiers and prevent DNA damage induced in human blood lymphocytes, as well as to mitigate the effects of radiation exposure. In this project, LYC, dissolved in DMSO at a concentration of 10, 20 or 40 µM/ml of cell suspension, was added to the isolated lymphocytes from human blood at appropriate intervals before or after the X-irradiation at doses of 0.5, 1 and 2 Gy. Cell viability in all groups was maintained at above 70%. The results showed the decrease of DNA damage in cells treated with various concentrations of LYC directly and 1 h before exposure to X-rays compared to the control group exposed to irradiation alone. Contrary results were observed in cells exposed to LYC immediately after exposure to ionizing radiation. The studies confirmed the protective effect of LYC against DNA damage induced by ionizing radiation, but after irradiation the carotenoid did not stimulate of DNA repair and cannot act as modifier. However, supplementation with LYC, especially at lower doses, may be useful in protection from radiation-induced oxidative damage.

Three generation study of reproductive and developmental toxicity following exposure of pubescent F0 male mice to di-n-butyl phthalate.

Humans are exposed to phthalates continuously throughout life. The aim of this study was to evaluate the genotoxic effects induced in male mice following 8 weeks of subchronic exposure to di-n-butyl phthalate (DBP) during their puberty and to investigate the possibility of transmission of mutations to subsequent generations via the sperm. Pzh:Sfis outbred male mice aged 4.5 weeks were exposed to DBP by gavage for 8 weeks, 3 days per week to doses of 1/16 LD50 or 1/4 LD50 each time. Six to seven males from each dosage group were sacrificed at 4, 8 and 12 weeks after the start of exposure for examination of sperm count and quality. Immediately after the end of exposure, the remaining males were caged for 1 week with two unexposed females each. Group of females were sacrificed 1 day before expected parturition, whilst other females were allowed to deliver and rear litters. F1 generation males at 8-9 weeks of age were caged with females from the same group, but from a different litter, for examination of prenatal development of the F2 generation. The remaining F1 generation males were sacrificed at the same age to check the sperm count and quality. Our results confirmed the toxic effects of DBP on the reproductive organs and germ cells of pubertally exposed males. The changes induced in male gametes might be transmitted to the next generation via the sperm. The most important effects were induced in the F1 generation. Exposure of F0 males to DBP induced skeletal malformations in surviving foetuses, caused significant mortality in postnatal life and a disturbance in the sex ratio (superior survival of females in F1), as well as increased frequency of DNA damage in the germ cells of F1 males. The present study did not confirm higher sensitivity to DBP of pubescent males compared to adult males, but the effects induced in the F1 generation differed from that after exposure of adult F0 males.

The effect of in vivo resveratrol supplementation in irradiated mice on the induction of micronuclei in peripheral blood and bone marrow reticulocytes.

The aim of the study was to investigate how coadministration of resveratrol (RSV) at different time after the start of irradiation influences the frequency of micronuclei (MN) in reticulocytes of bone marrow and peripheral blood, and if the RSV supplementation after termination of irradiation may influence the recovery process of damaged cells. Coadministration of RSV with 1-day delay after 1 Gy irradiation significantly decreased the levels of MN in bone marrow and in peripheral blood, whereas with 1-week delay, only in bone marrow reticulocytes. Above combined treatment did not improve the process of recovery. RSV supplementation with 1-day delay relatively to 0.5 Gy irradiation, significantly decreased the frequencies of MN, especially after coadministration with 28mg/kg bw of RSV. Coadministration of RSV since eighth day did not influence the frequencies of MN compared to irradiated cells. The recovery process in the presence of RSV proceeded faster. Supplementation of RSV following initiation of irradiation is beneficial in case of irradiation with lower doses. RSV should be supplemented as soon as possible. Supplementation of RSV after termination of irradiation significantly speed up the recovery. Current results confirmed the ability of RSV to mitigate the effect of irradiation.

Male-mediated F1 effects in mice exposed to bisphenol A, either alone or in combination with X-irradiation.

We investigated the possible transmission of heritable changes via the sperm, following preconceptional exposure of mice to bisphenol A (BPA), either alone or in combination with X-irradiation. Males were exposed for 8 weeks to BPA, X-rays or both agents, and mated to unexposed females. Pre- and postnatal development of the offspring of exposed males was examined. Both BPA alone and the combined exposure slightly affected postnatal development. Combined exposure induced two-fold higher postnatal mortality than BPA the alone, whereas BPA exposure caused reduced body weight and diminished sperm quality in F1 generation.

Lycopene - antioxidant with radioprotective and anticancer properties. A review.

UNLABELLED: Ionizing radiation may cause damage to living tissue by producing free radicals like reactive oxygen species (ROS). ROS can randomly react with lipids, proteins and nucleic acids of cell causing oxidative stress and damage in these macromolecules, leading to pathogenesis of chronic diseases and age related and also cancer. The first line of defense from the damaging effects of ROS is antioxidants, which convert the oxidants to less reactive species. Lycopene (LYC) is an acyclic isomer of beta-carotene. It synthesized by plants or autotrophic bacteria but not by animals. Red fruits and vegetables, including tomatoes, watermelons, pink grapefruits, apricots, pink guavas and papaya contain LYC. This carotenoid has very strong antioxidant properties. The many studies confirm that dietary supplementation with LYC reduces risk of cancers of many organs, but also retard the growth of the tumors. LYC has also chemopreventive effects against other diseases such as cardiovascular disease, osteoporosis, male infertility and inhibits the toxic action of other agents. Numerous in vitro and animal studies showed that LYC may provide protection against damages induced by ionizing radiation. It suggests that supplementation of LYC might be useful in diminishing of negative effect of cancer radiotherapy or in mitigating the effects of possible radiation accidents on human health. KEY WORDS: lycopene, antioxidants, anticarcinogenic agents, radioprotection.

The effect occupational exposure to ionizing radiation on the DNA damage in peripheral blood leukocytes of nuclear medicine personnel.

OBJECTIVES: The aim of this study was estimation of DNA strand breaks in leukocytes of peripheral blood of staff in a nuclear medicine department. METHODS: The exposed group consisted of 46 volunteers and the control group consisted of 40 volunteers. Samples consisting of 1 ml whole blood were collected by venepuncture. DNA damage in leukocytes was detected by alkaline comet assay. RESULTS: There was no correlation between the effective dose measured by individual dosimeters and DNA damage and no differences between sexes. The mean level of damage to DNA in people exposed to ionizing radiation was significantly elevated compared with control individuals. The highest value for mean comet tail moment was noted in leukocytes of PET/CT and scintigraphy technicians (1.28 vs. 0.30 for control, p=0.013). The levels of DNA damage in leukocytes of workers in category B (effective dose may exceed 1 mSv/year) were significantly enhanced. The DNA migration of leukocytes in exposed smokers and nonsmokers was similar. In the control group the damage to DNA of leukocytes in smokers was markedly but not significantly higher compared with nonsmokers. CONCLUSIONS: Occupational exposure to ionizing radiation leads to enhanced levels of reversible DNA damage in leukocytes of nuclear medicine employees. The level of DNA damage depends on the kind of work. Cigarette smoking is related to the increase in DNA damage in unexposed individuals but not in nuclear medicine workers. Radiation seems to be a stronger inducer of DNA damage than smoking. Although most of the DNA damage detected by comet assay is repaired, further improvement of radiation safety should be taken under consideration.

Comparison of the effects of bisphenol A alone and in a combination with X-irradiation on sperm count and quality in male adult and pubescent mice.

Bisphenol A (BPA) is employed in the manufacturing of epoxy, polyester-styrene, and polycarbonate resins, which are used for the production of baby and water bottles and reusable containers, food and beverage packing, dental fillings and sealants. The study was designed to examine the effects of 8-week exposure (a full cycle of spermatogenesis) to BPA alone and in a combination with X-irradiation on the reproductive organs and germ cells of adult and pubescent male mice. Pzh:Sfis male mice were exposed to BPA (5, 10, and 20 mg/kg) or X-rays (0.05 Gy) or to a combination of both (0.05 Gy + 5 mg/kg bw BPA). The following parameters were examined: sperm count, sperm motility, sperm morphology, and DNA damage in male gametes. Both BPA and X-rays alone diminished sperm quality. BPA exposure significantly reduced sperm count in pubescent males compared to adult mice, with degenerative changes detected in seminiferous epithelium. This may suggest a higher susceptibility of germ cells of younger males to BPA action. Combined BPA with X-ray treatment enhanced the harmful effect induced by BPA alone in male germ cells of adult males, whereas low-dose irradiation showed sometimes protective or additive effects in pubescent mice.

Genotoxicity of silver and titanium dioxide nanoparticles in bone marrow cells of rats in vivo.

Although nanomaterials have the potential to improve human life, their sideline effects on human health seem to be inevitable and still remain unknown. This study aimed to investigate the cytotoxicity and genotoxicity of titanium dioxide (TiO2) and silver (Ag) nanoparticles (NPs) at different doses and particle sizes to bone marrow cells. Both types of nanoparticles were chosen due to their wide applications of them in consumer products. Rats were injected intravenously with a single dose of 5 or 10 mg/kg bw of 20 nm AgNPs or with 5 mg/kg bw 200 nm AgNPs or with 5 mg/kg bw 21 nm TiO2NPs. The samples were taken at 24 h, 1 week and 4 weeks following the exposure. Micronucleus test and the Comet assay were used to detect DNA damage. Neither AgNPs nor TiO2NPs caused cytotoxicity to bone marrow red and white cells. The polychromatic erythrocytes are the main target of both nanoparticles. A single exposure to AgNPs induced significantly enhanced frequency of micronuclei not only at 24 h after exposure, but also 1 and 4 weeks later, whereas single exposure to TiO2NPs showed positive effect at 24 h only. Negative responses were shown in reticulocytes (micronuclei) and in leukocytes (Comet assay) of bone marrow. Results indicated that different bone marrow cells display different susceptibility toward genotoxicity mediated by both investigated nanoparticles. The use of materials containing nanoparticles and the potential health implication of them should be monitored.

Genotoxic effects of bisphenol A on somatic cells of female mice, alone and in combination with X-rays.

Bisphenol A (BPA), a monomer used in the manufacture of epoxy, polycarbonate, and polystyrene resins, is a xenoestrogen present in many consumer products. We investigated the effects of 2-week exposure to BPA, either alone or in combination with X-rays, on the induction of DNA damage in somatic cells of female mice in vivo. The micronucleus and alkaline comet assays were used to evaluate genotoxicity. BPA induced DNA strand breaks in lung cells but not in bone marrow lymphocytes, liver, kidney, or spleen cells. Induction of micronuclei was observed only in polychromatic reticulocytes of peripheral blood. Levels of damage following combination exposure to ionizing radiation plus BPA depended on tissue, assay, and time.

Silver nanoparticles effects on epididymal sperm in rats.

The motivation of our study was to examine the acute effects of intravenously administered a single bolus dose of silver nanoparticles (AgNPs) on rat spermatogenesis and seminiferous tubules morphology. In the treated rats compared to the vehicle treated control animals, the experiments revealed a size-dependent (20nm and 200nm), dose-dependent (5 and 10mg/kg body mass) and time-dependent (24h, 7 and 28days) decrease the epididymal sperm count measured by histological methods. In parallel AgNPs injection increased the level of DNA damage in germ cells, as measured by alkaline comet assay. Histological examination of the testes showed change in the testes seminiferous tubule morphometry in 200nm Ag NPs treated rats. No change of body weight, adipose tissue distribution and the frequency of abnormal spermatozoa was observed. Twenty nanometers AgNP appeared to be more toxic than 200nm ones.

[Induction of micronuclei in peripheral blood and bone marrow reticulocytes of male mice after subchronic exposure to x-rays and bisphenol A]. / Indukcja mikrojader w krwi obwodowej i szpiku kostnym samców myszy narazanych subchronicznie na dzialanie promieniowania x i bisfenolu A.

BACKGROUND: Ionizing radiation and xenoestrogens are widely present in the human environment. Bisphenol A (BPA) is used to manufacture polycarbonate plastics, epoxy and polyester resins. BPA is present in a great variety of products including: baby bottles, compact disks, thermal paper, safety helmets, bullet resistant laminate, plastic windows, car parts, adhesives, protective coatings, powder paints, polycarbonate bottles and containers, the sheathing of electrical and electronic parts, dental fillings. Food and beverage cans are protected from rusting and corrosion by the application of epoxy resins as inner coatings. Human activities involving the use of radiation and radioactive materials in industry, agriculture and research cause radiation exposure in addition to natural exposure coming from cosmic rays and naturally occurring radioactive substances. OBJECTIVE: The aim of the study was to estimate the effects of bisphenol A, X-rays and combined exposure to X-rays and bisphenol A on the induction of micronuclei in the peripheral blood and in bone marrow reticulocytes of laboratory mice. MATERIAL AND METHOD: Pzh-Sfis male mice were exposed for 8 weeks. Animals were treated with bisphenol A diluted in drinking water (5 mg/kg bw, 10 mg/kg bw, 20 mg/kg bw), irradiated 0.05 Gy of X-rays or exposed to a combination of both (0.05 Gy + 5 mg/kg bw BPA). The samples of peripheral blood were taken at 1, 4 and 8 week following the start of exposure, whereas the bone marrow after the end of experiment, only. The induction of micronuclei in reticulocytes were evaluated by using fluorescence microscope. RESULTS: Bisphenol A as well as ionizing radiation stimulated induction of micronuclei in peripheral blood and bone marrow reticulocytes. After the irradiation the level of micronuclei increased, whereas after exposure to BPA decreased related to time expired from beginning of experiment. Combined exposure of ionizing radiation and bisphenol A induced significantly higher frequency of micronuclei compared to the effect produced by BPA alone. The frequency of micronuclei in peripheral blood reticulocytes increased during the experiment. In all groups, the significantly lower induction ofmicronuclei in reticulocytes of bone marrow than of peripheral blood were observed. The levels ofmicronuclei in mice exposed to a combination of X-rays and BPA or to irradiation alone were slightly higher compared to those administered to BPA alone. CONCLUSIONS: Bisphenol A induced micronuclei in peripheral blood and bone marrow reticulocytes. Subchronic BPA exposure leads to diminished sensitivity of genetic material of reticulocytes on the induction of damage. X-rays is probably the agent which decided about DNA damage following combined exposure.

[The influence of bisphenol A and of combined exposure to X-rays and bisphenol A to somatic cells of the bone marrow and liver of mice]. / Wplyw bisfenolu A i skojarzonego dzialania bisfenolu A i promieniowania X na komórki somatyczne szpiku kostnego i watroby myszy.

The aim of study was to estimate the effects of bisphenol A (BPA) and combined exposure to X-rays and BPA to somatic cells of the bone marrow and liver of mice. Male mice Pzh: Sfis were irradiated with 0.05 Gy or treated with BPA (5 mg/kg mc, 10 mg/kg mc, 20 mg/kg mc) or exposed to a combination of both (0.05 Gy + 5 mg/kg BPA) for 8 weeks. Samples were taken at 24h, 1, 4 and 8 weeks after the end of exposure. Our study showed, that BPA can induce, measured by Comet assay, DNA damage in limphocytes of the bone marrow. The induction of DNA damage in somatic cells of the liver was not detected. After combined exposure to both agents a greater migration of DNA in cells of both organs than after the exposure to bisphenol A alone was observed. Probably the X-rays intensify the genotoxicity of BPA.