1
|
Jiang DW, Wang QR, Shen XR, He Y, Qian TT, Liu Q, Hou DY, Liu YM, Chen W, Ren X, Li KX. Radioprotective effects of cimetidine on rats irradiated by long-term, low-dose-rate neutrons and 60Co γ-rays. Mil Med Res 2017; 4:7. [PMID: 28261494 PMCID: PMC5327571 DOI: 10.1186/s40779-017-0116-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 02/18/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combined with γ-rays. This study was carried out to evaluate the protective effects of cimetidine on rats exposed to long-term, low-dose-rate neutron and γ-ray combined irradiation (n-γ LDR). METHODS Fifty male Sprague-Dawley (SD) rats were randomly divided into 5 groups: the normal control group, radiation model group, 20 mg/(kg · d) cimetidine group, 80 mg/(kg · d) cimetidine group and 160 mg/(kg · d) cimetidine group (10 rats per group). Except for the normal control group, 40 rats were simultaneously exposed to fission neutrons (252Cf, 0.085 mGy/h) for 22 h every day and γ-rays (60Co, 0.097 Gy/h) for 1.03 h once every three days, and the cimetidine groups were administered intragastrically with cimetidine at doses of 20, 80 and 160 mg/kg each day. Peripheral blood WBC of the rats was counted the day following exposure to γ-rays. The rats were anesthetized and sacrificed on the day following exposure to 252Cf for 28 days. The spleen, thymus, testicle, liver and intestinal tract indexes were evaluated. The DNA content of bone marrow cells and concanavalin A (ConA)-induced lymphocyte proliferation were measured. The frequency of micronuclei in polychromatic erythrocytes (fMNPCEs), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in the serum and liver tissues were detected. RESULTS The peripheral blood WBC in the cimetidine groups was increased significantly on the 8th day and the 26th day compared with those in the radiation model group. The spleen, thymus and testicle indexes of the cimetidine groups were higher than those of the radiation model group. The DNA content of bone marrow cells and lymphocyte proliferation in the cimetidine groups were increased significantly, and fMNPCE was reduced 1.41-1.77 fold in cimetidine treated groups. The activities of SOD and GSH-Px in the cimetidine groups were increased significantly, and the content of MDA in the cimetidine groups was decreased significantly. CONCLUSIONS The results suggested that cimetidine alleviated damage induced by long-term, low-dose-rate neutron and γ combined irradiation via antioxidation and immunomodulation. Cimetidine might be useful as a potent radioprotector for radiotherapy patients as well as for occupational exposure workers.
Collapse
Affiliation(s)
- Ding-Wen Jiang
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Qing-Rong Wang
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Xian-Rong Shen
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Ying He
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Tian-Tian Qian
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Qiong Liu
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Deng-Yong Hou
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Yu-Ming Liu
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Wei Chen
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Xin Ren
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| | - Ke-Xian Li
- The PLA Key Laboratory of Biological Effect and Medical Protection on Naval Vessel Special Environment, Naval Medical Research Institute, Xiangyin Road 880, Shanghai, 200433 China
| |
Collapse
|
2
|
Ng C, Kong E, Konishi T, Kobayashi A, Suya N, Cheng S, Yu K. Low-dose neutron dose response of zebrafish embryos obtained from the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility. Radiat Phys Chem Oxf Engl 1993 2015. [DOI: 10.1016/j.radphyschem.2015.05.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
3
|
Otsuka K, Iwasaki T. Effects of dose rates on radiation-induced replenishment of intestinal stem cells determined by Lgr5 lineage tracing. JOURNAL OF RADIATION RESEARCH 2015; 56:615-22. [PMID: 25832104 PMCID: PMC4497386 DOI: 10.1093/jrr/rrv012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 02/16/2015] [Indexed: 05/05/2023]
Abstract
An understanding of the dynamics of intestinal Lgr5(+) stem cells is important for elucidating the mechanism of colonic cancer development. We previously established a method for evaluating Lgr5(+) stem cells by tamoxifen-dependent Lgr5-lineage tracing and showed that high-dose-rate radiation stimulated replenishment of colonic stem cells. In this study, we evaluated the effects of low-dose-rate radiation on stem cell maintenance. Tamoxifen (4OHT)-injected Lgr5-EGFP-IRES-Cre(ERT2) × ROSA-LSL-LacZ mice were used, LacZ-labeled colonic crypts were enumerated, and the loss of LacZ(+) crypts under low-dose-rate radiation was estimated. After 4OHT treatment, the number of LacZ-labeled Lgr5(+) stem cells was higher in the colon of infant mice than in adult mice. The percentage of LacZ-labeled crypts in infant mice rapidly decreased after 4OHT treatment. However, the percentage of labeled crypts plateaued at ∼2% at 4 weeks post-treatment and remained unchanged for up to 7 months. Thus, it will be advantageous to evaluate the long-term effects of low-dose-rate radiation. Next, we determined the percentages of LacZ-labeled crypts irradiated with 1 Gy administered at different dose rates. As reported in our previous study, mice exposed to high-dose-rate radiation (30 Gy/h) showed a marked replenishment (P = 0.04). However, mice exposed to low-dose-rate radiation (0.003 Gy/h) did not exhibit accelerated stem-cell replenishment (P = 0.47). These findings suggest the percentage of labeled crypts can serve as a useful indicator of the effects of dose rate on the stem cell pool.
Collapse
Affiliation(s)
- Kensuke Otsuka
- Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo 201-8511, Japan
| | - Toshiyasu Iwasaki
- Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), 2-11-1 Iwado-kita, Komae, Tokyo 201-8511, Japan
| |
Collapse
|
4
|
Jee YH, Jeong WI, Kim TH, Hwang IS, Ahn MJ, Joo HG, Hong SH, Jeong KS. p53 and cell-cycle-regulated protein expression in small intestinal cells after fast-neutron irradiation in mice. Mol Cell Biochem 2005; 270:21-8. [PMID: 15792350 DOI: 10.1007/s11010-005-3440-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The involvement of the p53 gene in apoptosis of many cell types towards y-radiation is well established. However, little information is available on the relationship between p53 status and cells' ability to undergo apoptosis following exposure to fast neutrons. The aim of this study was to characterize the apoptotic pathway traveled by neutrons in mouse intestinal crypt cells. Each mouse received whole body doses of 0.25-8 Gy fast neutrons and were sacrificed 0, 4, 6, 12, 24, 48, and 72 h, respectively, after irradiation. Apoptosis of crypt cells and expression of p53, cyclin A, cyclin B, cyclin D, and cyclin E were measured. The apoptosis in crypt cells was maximal at 4 and 6 h after irradiation, showing a gradual decline at 24 h. The highest frequency of apoptosis was seen at a 1 Gy dose and then declined gradually beyond a 2 Gy dose with high levels of damage. In immunoblot analysis, apoptosis was confirmed to be dependent on p53 function after fast-neutron irradiation. In addition, cyclin B1, cyclin D, and cyclin E were overexpressed in intestinal cells after fast-neutron irradiation and their immunoreactivities were increased strongly in round and oval cells of laminar propria in villi core and crypts. The results of the current study suggest that apoptosis in crypt cells shows a time- and dose-dependent increase after fast-neutron irradiation. In addition, fast-neutron-induced apoptosis in mouse intestinal crypt cells appears to be related to the increase in functional p53 proteins to a level sufficient to initiate apoptosis and up-regulation of cell-cycle-regulated proteins, which may lead to resistance to DNA damage through cell cycle arrest, is involved deeply in protection of gastrointestinal cells after low doses of fast-neutron irradiation.
Collapse
Affiliation(s)
- Young-Heun Jee
- Department of Veterinary Medicine, Cheju National University, Cheju, South Korea
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Ruttenber AJ, Harrison LT, Baron A, McClure D, Glanz J, Quillin R, O'Neill JP, Sullivan L, Campbell J, Nicklas JA. hprt mutant frequencies, nonpulmonary malignancies, and domestic radon exposure: "postmortem" analysis of an interesting hypothesis. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2001; 37:7-16. [PMID: 11170237 DOI: 10.1002/1098-2280(2001)37:1<7::aid-em1001>3.0.co;2-h] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The hypothesis that exposure to domestic radon raises the risk for leukemia and other nonpulmonary cancers has been proposed and tested in a number of epidemiologic studies over the past decade. During this period, interest in this hypothesis was heightened by evidence of increased frequencies of mutations at the hypoxanthine guanine phosphoribosyl transferase (hprt) gene in persons exposed to domestic radon (Bridges BA et al. [1991]: Lancet 337:1187-1189). An extension of this study (Cole J et al. [lsqb[1996]: Radiat Res 145:61-69) and two independent studies (Albering HJ et al. [1992[: Lancet 340:739; Albering HJ et al. [1994[: Lancet 344:750-751) found that hprt mutant frequency was not correlated with domestic radon exposure, and two well-designed epidemiologic studies showed no evidence of a relation between radon exposure and leukemia in children or adults. In this report, we present additional data from a study of Colorado high school students showing no correlation between domestic radon exposure and hprt mutant frequency. We use reanalyses of previous studies of radon and hprt mutant frequency to identify problems with this assay as a biomarker for domestic radon exposure and to illustrate difficulties in interpreting the statistical data. We also show with analyses of combined data sets that there is no support for the hypothesis that domestic radon exposure elevates hprt mutant frequency. Taken together, the scientific evidence provides a useful example of the problems associated with analyzing and interpreting data that link environmental exposures, biomarkers, and diseases in epidemiologic studies.
Collapse
Affiliation(s)
- A J Ruttenber
- Department of Preventive Medicine and Biometrics, University of Colorado School of Medicine, 4200 E. Ninth Avenue, Campus Box C-245, Denver, CO 80262, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
6
|
Kinashi Y, Sakurai Y, Masunaga S, Suzuki M, Takagaki M, Akaboshi M, Ono K. Molecular structural analysis of HPRT mutations induced by thermal and epithermal neutrons in Chinese hamster ovary cells. Radiat Res 2000; 154:313-8. [PMID: 10956438 DOI: 10.1667/0033-7587(2000)154[0313:msaohm]2.0.co;2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Chinese hamster ovary (CHO) cells were exposed to thermal and epithermal neutrons, and the occurrence of mutations at the HPRT locus was investigated. The Kyoto University Research Reactor (KUR), which has been improved for use in neutron capture therapy, was the neutron source. Neutron energy spectra ranging from nearly pure thermal to epithermal can be chosen using the spectrum shifters and thermal neutron filters. To determine mutant frequency and cell survival, cells were irradiated with thermal and epithermal neutrons under three conditions: thermal neutron mode, mixed mode with thermal and epithermal neutrons, and epithermal neutron mode. The mutagenicity was different among the three irradiation modes, with the epithermal neutrons showing a mutation frequency about 5-fold that of the thermal neutrons and about 1.5-fold that of the mixed mode. In the thermal neutron and mixed mode, boron did not significantly increase the frequency of the mutants at the same dose. Therefore, the effect of boron as used in boron neutron capture therapy (BNCT) is quantitatively minimal in terms of mutation induction. Over 300 independent neutron-induced mutant clones were isolated from 12 experiments. The molecular structure of HPRT mutations was determined by analysis of all nine exons by multiplex polymerase chain reaction. In the thermal neutron and mixed modes, total and partial deletions were dominant and the fraction of total deletions was increased in the presence of boron. In the epithermal neutron mode, more than half of the mutations observed were total deletions. Our results suggest that there are clear differences between thermal and epithermal neutron beams in their mutagenicity and in the structural pattern of the mutants that they induce. Mapping of deletion breakpoints of 173 partial-deletion mutants showed that regions of introns 3-4, 7/8-9 and 9-0 are sensitive to the induction of mutants by neutron irradiation.
Collapse
Affiliation(s)
- Y Kinashi
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | | | | | | | | | | | | |
Collapse
|
7
|
Kinashi Y, Sakurai Y, Masunaga S, Suzuki M, Akaboshi M, Ono K. Dimethyl sulfoxide protects against thermal and epithermal neutron-induced cell death and mutagenesis of Chinese hamster ovary (CHO) cells. Int J Radiat Oncol Biol Phys 2000; 47:1371-8. [PMID: 10889392 DOI: 10.1016/s0360-3016(00)00588-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
PURPOSE To investigate the protective effects of dimethyl sulfoxide (DMSO) on cell killing and mutagenicity at the HPRT locus in Chinese hamster ovary (CHO) cells against thermal and epithermal neutrons produced at the Kyoto University Research (KUR) reactor. METHODS AND MATERIALS DMSO was added to cells 15 min before irradiation and removed 15 min after irradiation. Cells were irradiated by thermal and epithermal neutrons with or without boron at 10 ppm. The biological endpoint of cell survival was measured by colony formation assay. The mutagenicity was measured by the mutant frequency in the HPRT locus. A total of 378 independent neutron-induced mutant clones were isolated in separate experiments. The molecular structure of HPRT mutations was determined by analysis by multiplex polymerase chain reaction of all nine exons. RESULTS The D(0) values of epithermal and thermal neutrons in three different modes, i.e., thermal, epithermal, and mixtures of thermal and epithermal, were 0.8-1.2 Gy. When cells were treated with DMSO, the D(0) values increased to 1.0-2.3, especially in the absence of boron. DMSO showed a protective effect against mutagenesis of the HPRT locus induced by epithermal and thermal neutron irradiation. After DMSO treatment, the mutagenicity was decreased, especially when the cells were irradiated in epithermal neutron mode. Molecular structure analysis indicated that total and partial deletions were dominant and the incidence of total deletions was increased in the presence of boron in the thermal neutron and mixed modes. In the epithermal neutron mode, more than half of the mutations were total deletions. When cells were treated with DMSO, the incidence of total deletions by thermal neutron irradiation with boron and epithermal irradiation decreased. CONCLUSIONS Our results suggest that DMSO has various protective effects against cytotoxic and mutagenic effects of thermal and epithermal neutrons, and that the extent of protection is reflected by the percentage of absorbed dose distribution for each neutron irradiation mode.
Collapse
Affiliation(s)
- Y Kinashi
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka, Japan.
| | | | | | | | | | | |
Collapse
|
8
|
Mozdarani H, Khoshbin-Khoshnazar AR. In vivo protection by cimetidine against fast neutron-induced micronuclei in mouse bone marrow cells. Cancer Lett 1998; 124:65-71. [PMID: 9500193 DOI: 10.1016/s0304-3835(97)00451-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We have previously shown that cimetidine is capable of reducing the clastogenic effect of gamma-rays. In this research the radioprotective property of this drug was examined against low doses of fast neutrons using the micronucleus assay. Swiss albino male mice (12 weeks old) were irradiated by fast neutrons emitted from a 241Am-9Be source. The absorbed doses were 1.5, 2.25, 3.375 and 5.06 cGy at a dose rate of 0.718 cGy/h. Two hours prior to neutron irradiation mice were treated by cimetidine at a concentration of 15 mg/kg body weight injected i.p. Mice were sacrificed by cervical dislocation at different post-irradiation times (24, 48 and 72 h). The results obtained show that the frequency of neutron-induced micronuclei in polychromatic erythrocytes (PCEs) is significantly higher than those of control groups (P < 0.05) at the neutron doses used in these experiments. Moreover, cimetidine effectively reduced (1.5-2-fold) the frequency of micronuclei in PCE (P < 0.05). These results show that cimetidine can protect bone marrow cells against clastogenic effects of low dose fast neutrons and hence high linear energy transfer (LET) radiation. The mechanism by which cimetidine reduces the clastogenic effects of fast neutrons is not fully understood. It might act through a free radical scavenging mechanism associated with the amplification of the glutathione system.
Collapse
Affiliation(s)
- H Mozdarani
- School of Medical Sciences, Tarbiat Modarres University, Tehran, Iran
| | | |
Collapse
|
9
|
Kinashi Y, Masunaga S, Takagaki M, Ono K. Mutagenic effects at HPRT locus induced in Chinese hamster ovary cells by thermal neutrons with or without boron compound. Mutat Res 1997; 377:211-5. [PMID: 9247616 DOI: 10.1016/s0027-5107(97)00074-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
CHO cells were exposed to thermal neutrons and their mutation frequency was determined. The Kyoto University Research Reactor (KUR), which has a very low level of contamination by gamma-rays and fast neutrons was used as a thermal neutron source. Cells were irradiated in the presence or absence of boric acid to determine mutation frequency and cell survival. Thermal neutron irradiation was 2.5 times as mutagenic as gamma-irradiation without boron. In the presence of boron, however, thermal neutron irradiation was from 4.2 to 4.5 times as mutagenic as gamma-irradiation. When the mutation frequency was plotted against the survival fraction, a higher degree of mutagenicity was observed in the presence than in the absence of boron. These results suggest that the enhancement of thermal neutron-induced mutation with boron is strongly associated with alpha-particles released by 10B(n, alpha)7 Li reaction.
Collapse
Affiliation(s)
- Y Kinashi
- Research Reactor Institute, Kyoto University, Osaka, Japan
| | | | | | | |
Collapse
|
10
|
Woloschak GE, Felcher P, Chang-Liu CM. Expression of cytoskeletal and matrix genes following exposure to ionizing radiation: dose-rate effects and protein synthesis requirements. Cancer Lett 1995; 92:135-41. [PMID: 7600523 DOI: 10.1016/0304-3835(95)03767-q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Experiments were designed to examine the effects of radiation dose-rate and cycloheximide on expression of cytoskeletal and matrix elements in Syrian hamster embryo cells. Results here demonstrated little effect of dose-rate for fission-spectrum neutrons when comparing expression of alpha-tubulin or fibronectin genes. Effects of cycloheximide, however, revealed several findings: (a) Cycloheximide repressed accumulation of alpha-tubulin following exposure to high dose-rate neutrons or gamma-rays. (b) Cycloheximide did not affect accumulation of mRNA for actin genes. (c) Cycloheximide abrogated the moderate induction of fibronectin-mRNA which occurred following exposure to gamma-rays and high dose-rate neutrons. These results suggest a role for labile proteins in the maintenance of alpha-tubulin and fibronectin mRNA accumulation following exposure to ionizing radiation.
Collapse
Affiliation(s)
- G E Woloschak
- Center for Mechanistic Biology and Biotechnology, Argonne National Laboratory, Illinois 60439-4811, USA
| | | | | |
Collapse
|