- 著者
- Hirokatsu Saito Kentaro Tanemura Yusuke Furukawa Takahiro Sasaki Jun Kanno Satoshi Kitajima
- 出版者
- The Japanese Society of Toxicology
- 雑誌
- The Journal of Toxicological Sciences (ISSN:03881350)
- 巻号頁・発行日
- vol.48, no.4, pp.203-210, 2023 (Released:2023-04-03)
- 参考文献数
- 32
Acetamiprid (ACE), a neonicotinoid chemical, is widely used as a pesticide due to its rapid insecticidal activity. Although neonicotinoids exert very low toxicity in mammals, the effects of early exposure to neonicotinoids on the adult central nervous system are poorly understood. This study investigated the effects of ACE exposure in early life on brain function in adult mice. We exposed male C57BL/6N mice to ACE (10 mg/kg) orally when they were two (postnatal lactation) or 11 weeks old (adult). We examined the effects of ACE on the central nervous system using the mouse behavioral test battery, consisting of the open field test, light/dark transition test, elevated plus-maze test, contextual/cued fear conditioning test, and pre-pulse inhibition test at 12–13 weeks old. In the mouse behavioral test battery, learning memory abnormalities were detected in the mature treatment group. In addition, learning memory and emotional abnormalities were detected in the postnatal lactation treatment group. These results suggest that the behavioral effects of postnatal lactation treatment with ACE were qualitatively different from the behavioral abnormalities in the mature treatment group.
- 著者
- Yuhji Taquahashi Shuji Tsuruoka Koichi Morita Masaki Tsuji Kousuke Suga Ken-ich Aisaki Satoshi Kitajima
- 出版者
- The Japanese Society of Toxicology
- 雑誌
- Fundamental Toxicological Sciences (ISSN:2189115X)
- 巻号頁・発行日
- vol.9, no.1, pp.17-21, 2022 (Released:2022-01-18)
- 参考文献数
- 10
Carbon-nanotube yarn (CNT-Y) made from high-purity, highly crystalized, double-walled carbon nanotubes is an advanced material with excellent electrical conductivity and flexibility; hence, it could potentially be used as a novel electrode for biopotential measurements. To our knowledge, the present study is the first in which CNT-Y electrodes were used to conduct electrocardiography (ECG) and electroencephalography (EEG) on experimental animals. All procedures and biopotential measurements were performed under isoflurane anesthesia. The CNT-Y electrodes were attached to the animals by creating a single interrupting suture on the skin. The lead II electrode configuration was used for ECG recording, i.e., the positive, negative, and body-earth electrodes were placed on the left apex of the auricular surface, the interscapular region, and the cervical region, respectively. The bipolar lead was used for EEG recording, with the exploring and reference electrodes on the bregma and base of the right auricular surface, respectively. Using CNT-Y electrodes, we obtained a clear ECG waveform from rats and a guinea pig; the QRS amplitude was ~1.4 mV. In rats, we obtained an EEG waveform with an amplitude of ~150 µV; the peak frequency was 0.8 Hz and the range was ~3 Hz according to power spectral density analysis. In the guinea pig, we obtained an EEG waveform with an amplitude of ~500 µV; the first peak was 0.1 Hz, the second peak was 1 Hz, and the range was ~3 Hz. These results show that CNT-Y could be used in toxicology studies to easily and inexpensively obtain high-resolution biological signals.
- 著者
- Atsuya Takagi Akihiko Hirose Tetsuji Nishimura Nobutaka Fukumori Akio Ogata Norio Ohashi Satoshi Kitajima Jun Kanno
- 出版者
- The Japanese Society of Toxicology
- 雑誌
- The Journal of Toxicological Sciences (ISSN:03881350)
- 巻号頁・発行日
- vol.33, no.1, pp.105-116, 2008 (Released:2008-02-26)
- 参考文献数
- 22
- 被引用文献数
- 428 655
Nanomaterials of carbon origin tend to form various shapes of particles in micrometer dimensions. Among them, multi-wall carbon nanotubes (MWCNT) form fibrous or rod-shaped particles of length around 10 to 20 micrometers with an aspect ratio of more than three. Fibrous particles of this dimension including asbestos and some man-made fibers are reported to be carcinogenic, typically inducing mesothelioma. Here we report that MWCNT induces mesothelioma along with a positive control, crocidolite (blue asbestos), when administered intraperitoneally to p53 heterozygous mice that have been reported to be sensitive to asbestos. Our results point out the possibility that carbon-made fibrous or rod-shaped micrometer particles may share the carcinogenic mechanisms postulated for asbestos. To maintain sound activity of industrialization of nanomaterials, it would be prudent to implement strategies to keep good control of exposure to fibrous or rod-shaped carbon materials both in the workplace and in the future market until the biological/ carcinogenic properties, especially of their long-term biodurability, are fully assessed.