ミヤヤマ　タカミツ   Takamitsu Miyayama   宮山　貴光    所属   医学部 医学科    職種   助教
言語種別	英語
発表タイトル	Metabolic behavior and effects of ion and nanoparticle forms of silver in the mouse lung and macrophages
会議名	53rd annual meeting and ToxExpo: Society of Toxicology 2014
学会区分	国際学会及び海外の学会
発表形式	ポスター掲示
講演区分	一般
発表者・共同発表者	◎MIYAYAMA Takamitsu, ARAI Yuta, HIRANO Seishiro
発表年月日	2014/03/25
開催地 （都市, 国名）	Phoenix, USA
学会抄録	The Toxicologist in 53rd Annual Meeting and ToxExpo: Society of Toxicology 213 2014
概要	Health effects of silver nanoparticles (AgNPs) have not been well investigated, although AgNPs are now widely used in consumer products. We have investigated metabolic behavior and inflammatory responses of intratracheally instilled AgNPs and silver nitrate (AgNO3) in the mouse lungs. Male ICR mice were administered with AgNPs or AgNO3 at a dose of 10μg Ag per animal. Contents of Ag in lungs of the AgNPs-treated mice were significantly and 4.27 and 4.47 times higher than those of the AgNO3-treated mice at 4 and 24 h post administration, respectively. In the AgNO3-treated mice, Ag concentration in the lungs was not changed between 4 and 24 h. To evaluate neutrophil and pro-inflammatory cytokines after AgNPs or AgNO3 instillation, we performed bronchoalveolar lavage (BAL) to mice. AgNO3 significantly increased numbers of neutrophils at 24 h after instillation. On the other hand, AgNPs slightly increased neutrophil numbers at 24 h. In the BAL fluid (BALF), the concentrations of IL-1β significantly increased 24 h after AgNO3 and AgNPs instillation. We also investigated uptake and intracellular distribution of Ag in vitro exposing mouse macrophage cell cells (J774.1) to either AgNO3 or AgNPs. Ag was located to the insoluble fraction of the cells after exposure to AgNPs in a time dependent manner. Ag bound metallothionein (MT), which was measured by HPLC-ICP-MS, increased up to 3 h in J774.1 cells following exposure to AgNO3. On the other hand, Ag was not distributed to MTs and localized in lysosomes following exposure to AgNPs. These results suggest that AgNPs were first incorporated in lysosomes of macrophages and induced inflammatory stimuli to the cells or tissues. In contrast AgNO3 probably induced inflammatory stimuli first and increased Ag-bound MT levels in the cytosol.
researchmap用URL	http://www.toxicology.org/AI/MEET/AM2014/