title: Neurotoxicity of Silver Nanoparticles in Rat Brain After Intragastric Exposure.
abstract: It is known that the biological half-life of silver in the central nervous system is longer than in other organs. However, the potential toxicity of silver nanoparticles (NPs) on brain tissue and the underlying mechanism(s) of action are not well understood. In this study, neurotoxicity of silver NPs was examined in rat after intragastric administration. After a two-week exposure to low-dose (1 mg/kg, body weight) or high-dose (10 mg/kg) silver NPs, the pathological and ultrastructural changes in brain tissue were evaluated with H&E staining and transmission electron microscopy. The mRNA expression levels of key tight junction proteins of the blood-brain barrier (BBB) were analyzed by real-time RT-PCR, and several inflammatory factors were assessed in blood using ELISA assay. We observed neuron shrinkage, cytoplasmic or foot swelling of astrocytes, and extra-vascular lymphocytes in silver NP exposure groups. The cadherin 1 (2(-ΔΔCt): 1.45-fold/control) and Claudin-1 (2(-ΔΔCt): 2.77-fold/control) were slightly increase in mRNA expression levels, and IL-4 significantly increased after silver NP exposure. It was suggest that silver NP can induce neuronal degeneration and astrocyte swelling, even with a low-dose (1 mg/kg) oral exposure. One potential mechanism for the effects of silver NPs to the nervous cells is involved in inflammatory effects.
authors.forename: Liming
authors.initials: L
authors.lastname: Xu
authors.forename: Anliang
authors.initials: A
authors.lastname: Shao
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Zhao
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Wang
authors.forename: Cuiping
authors.initials: C
authors.lastname: Zhang
authors.forename: Yilin
authors.initials: Y
authors.lastname: Sun
authors.forename: Jie
authors.initials: J
authors.lastname: Deng
authors.forename: Laisheng Lee
authors.initials: LL
authors.lastname: Chou
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001921:Brain / Q000166:cytology / Q000187:drug effects / Q000473:pathology; D001923:Brain Chemistry / Q000187:drug effects*; D005260:Female; D053768:Metal Nanoparticles / Q000737:chemistry / Q000633:toxicity*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012834:Silver / Q000032:analysis / Q000097:blood / Q000737:chemistry / Q000633:toxicity*; D062725:Tight Junction Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D062725:Tight Junction Proteins; D012834:Silver