title: Analysis of the Effect of Chronic and Low-Dose Radiation Exposure on Spermatogenic Cells of Male Large Japanese Field Mice ( Apodemus speciosus ) after the Fukushima Daiichi Nuclear Power Plant Accident.
abstract: In this study we analyzed the effect of chronic and low-dose-rate (LDR) radiation on spermatogenic cells of large Japanese field mice ( Apodemus speciosus ) after the Fukushima Daiichi Nuclear Power Plant (FNPP) accident. In March 2014, large Japanese field mice were collected from two sites located in, and one site adjacent to, the FNPP ex-evacuation zone: Tanashio, Murohara and Akogi, respectively. Testes from these animals were analyzed histologically. External dose rate from radiocesium (combined134Cs and137Cs) in these animals at the sampling sites exhibited 21 μGy/day in Tanashio, 304-365 μGy/day in Murohara and 407-447 μGy/day in Akogi. In the Akogi group, the numbers of spermatogenic cells and proliferating cell nuclear antigen (PCNA)-positive cells per seminiferous tubule were significantly higher compared to the Tanashio and Murohara groups, respectively. TUNEL-positive apoptotic cells tended to be detected at a lower level in the Murohara and Akogi groups compared to the Tanashio group. These results suggest that enhanced spermatogenesis occurred in large Japanese field mice living in and around the FNPP ex-evacuation zone. It remains to be elucidated whether this phenomenon, attributed to chronic exposure to LDR radiation, will benefit or adversely affect large Japanese field mice.
authors.affiliation: a   Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishiku, Niigata, 950-2181, Japan.
authors.forename: Sachio
authors.initials: S
authors.lastname: Takino
authors.affiliation: a   Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishiku, Niigata, 950-2181, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yamashiro
authors.affiliation: a   Graduate School of Science and Technology, Niigata University, 2-8050 Ikarashi, Nishiku, Niigata, 950-2181, Japan.
authors.forename: Yukou
authors.initials: Y
authors.lastname: Sugano
authors.affiliation: b   Graduate School of Health Sciences Hirosaki University, 66-1 Honcho, Hirosaki, 036-8564, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Fujishima
authors.affiliation: c   Division of Life Science, Hokkaido Pharmaceutical University School of Pharmacy, 7-15-4-1 Maeda, Teine, Sapporo, 006-8590, Japan; and.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Nakata
authors.affiliation: b   Graduate School of Health Sciences Hirosaki University, 66-1 Honcho, Hirosaki, 036-8564, Japan.
authors.forename: Kosuke
authors.initials: K
authors.lastname: Kasai
authors.affiliation: d   Institute of Development, Aging and Cancer and.
authors.forename: Gohei
authors.initials: G
authors.lastname: Hayashi
authors.affiliation: d   Institute of Development, Aging and Cancer and.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Urushihara
authors.affiliation: d   Institute of Development, Aging and Cancer and.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: e   Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Aobaku, Sendai, 980-8575, Japan.
authors.forename: Hisashi
authors.initials: H
authors.lastname: Shinoda
authors.affiliation: b   Graduate School of Health Sciences Hirosaki University, 66-1 Honcho, Hirosaki, 036-8564, Japan.
authors.forename: Tomisato
authors.initials: T
authors.lastname: Miura
authors.affiliation: d   Institute of Development, Aging and Cancer and.
authors.forename: Manabu
authors.initials: M
authors.lastname: Fukumoto
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D001835:Body Weight / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D062406:Fukushima Nuclear Accident; D008297:Male; D051189:Murinae; D009929:Organ Size / Q000528:radiation effects; D013091:Spermatogenesis / Q000528:radiation effects*; D013737:Testis / Q000033:anatomy & histology / Q000528:radiation effects; D013997:Time Factors