- 著者
- Hiroki Yoshioka Tsunemasa Nonogaki Yasuro Shinohara Masumi Suzui Yurie Mori Gi-Wook Hwang Katsumi Ohtani Nobuhiko Miura
- 出版者
- The Japanese Society of Toxicology
- 雑誌
- The Journal of Toxicological Sciences (ISSN:03881350)
- 巻号頁・発行日
- vol.43, no.2, pp.129-134, 2018 (Released:2018-02-26)
- 参考文献数
- 28
- 被引用文献数
- 7
The aim of the present study is to investigate the “chronotoxicity” of seven metal compounds (Hg, Pb, Ni, Cr, Cu, Zn, or Fe) by assessing how their toxicity varies with circadian periodicity. Male ICR mice were injected with each metal compound intraperitoneally at 6 different time points over the course of a day (zeitgeber time [ZT]: ZT2, ZT6, ZT10, ZT14, ZT18 and ZT22). Mortality was then monitored until 14 days after the injection. Our investigation demonstrated that mice were tolerant against Ni toxicity during dark phase, on the other hand, they were tolerant against Cr toxicity during light phase. The chronotoxicity of Hg and Pb seemed to be biphasic. Further, mice were susceptible to toxicities against Cu and Zn in the time zone during which light and dark were reversed. Interestingly, no significant differences were observed for Fe exposure at any time of the day. Our results propose that the chronotoxicology may provide valuable information regarding the importance of injection timing for not only toxicity evaluation tests but also the reproducibility of animal experiments. Furthermore, our data suggests that chronotoxicology may be an important consideration when evaluating the quality of risk assessments for night shift workers who may be exposed to toxic substances at various times of the day.
- 著者
- Takashi Toyama Gi-Wook Hwang Akira Naganuma
- 出版者
- 一般社団法人日本毒性学会
- 雑誌
- Fundamental Toxicological Sciences (ISSN:2189115X)
- 巻号頁・発行日
- vol.2, no.5, pp.227-228, 2015-12-09 (Released:2015-12-09)
- 参考文献数
- 5
- 被引用文献数
- 1 1
This study attempted to identify substances that are driven out of HEK293 cells by methylmercury. Metabolomic analysis revealed that the levels of 3-phenylpropionic acid, citrulline, lactic acid, ornithine, proline and beta-alanine in the cell culture medium were increased by the treatment of cells with methylmercury. Address to the mechanism underlying the release of these substances will provide useful information to elucidate the toxicity mechanism of methylmercury.
- 著者
- Mayuka Yamada Midori Suzuki Takuya Noguchi Takumi Yokosawa Yuto Sekiguchi Natsumi Mutoh Takashi Toyama Yusuke Hirata Gi-Wook Hwang Atsushi Matsuzawa
- 出版者
- The Pharmaceutical Society of Japan
- 雑誌
- BPB Reports (ISSN:2434432X)
- 巻号頁・発行日
- vol.3, no.1, pp.16-21, 2020 (Released:2020-11-26)
- 参考文献数
- 27
- 被引用文献数
- 4 7
Both NF-E2-related factor 2 (Nrf2) and heat shock protein 70 (HSP70) contribute to cellular defense to various stresses, and have emerged as candidates of therapeutic targets to improve or prevent tissue damage. Cefotaxime (CTX), a third-generation cephalosporin antibiotic, is conceived as a safe drug largely free from side effects. CTX exhibits broad-spectrum antimicrobial activity, and thereby, is most commonly prescribed for the treatment of infectious diseases induced by Gram-positive or Gram-negative bacteria. In this study, we unexpectedly found the beneficial properties of CTX that upregulate both Nrf2 and HSP70 to the extent that stress-induced damage is ameliorated. Non-toxic levels of reactive oxygen species (ROS) induced by CTX activated the Nrf2 pathway without cytotoxicity, which in turn upregulated HSP70. Interestingly, the cytotoxicity of Fas/CD95 ligand (FasL), a cytotoxic cytokine that strongly induces apoptosis, was significantly ameliorated by pre-treatment with CTX, most likely because of the upregulation of Nrf2 and HSP70. Our results therefore show novel properties of CTX, which raise the possibility that CTX works as a non-toxic therapeutic agent for preventing and repairing tissue damage.