[Influence of intranasal instilled titanium dioxide nanoparticles on monoaminergic neurotransmitters of female mice at different exposure time].
OBJECTIVE
To investigate the influence of intranasal instilling titanium dioxide (TiO2) nanoparticles on monoaminergic neurotransmitters at different-time exposure.


METHODS
CD female mice were intranasally instilled three different-sized (25 nm, 80 nm and 155 nm) TiO, suspension every other day in a dose of 50 mg/kg body weight. The control group was instilled the same volume of Milli-Q water. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to analyze the titanium contents in murine brain after exposure to TiO2 particles 2 days, 10 days, 20 days and 30 days. The monoaminergic neurotransmitters such as norepinephrine (NE), dopamine (DA), 5-hydroxytryptamine (5-HT), 5-hydroxyindole acetic acid (5-HIAA), 3, 4-dihydroxyphenylacetic acid (DOPAC), and homovanillic (HVA), were determined by reversed-phase high performance liquid chromatography (RP-HPLC) with electrochemical detector.


RESULTS
After exposure to TiO, nanoparticles 10 days, the titanium contents in murine brain were increased, the titanium content in the 25 nm group was up to (1059.3 +/- 293.5) ng/g. In 20 days, the titanium content decreased slowly with the metabolism of titanium in vivo, but it kept at a high level, the content decreased to (654.7 +/- 269.2) ng/g in the 25 nm group. After exposure to TiO2 nanoparticles 30 days, the titanium contents had no obviously change. Because of the accumulation of TiO, in the brain, the contents of NE and 5-HT increased significantly after exposure to 80 nm and 155 nm TiO, nanoparticles 20 days, while the decreased contents of DA, DOPAC, HVA and 5-HIAA were observed.


CONCLUSIONS
The inhaled TiO2 nanoparticles could be translocated to and deposited in murine brain after absorbing by nasal mucosa, and further influence the releases and metabolisms of monoaminergic neurotransmitters in brain.
Wang
Jiang-xue
JX
Laboratory for Bio-Environmental Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Beijing, China.
Li
Yu-feng
YF
Zhou
Guo-qiang
GQ
Li
Bai
B
Jiao
Fang
F
Chen
Chun-ying
CY
Gao
Yu-xi
YX
Zhao
Yu-liang
YL
Chai
Zhi-fang
ZF
D000281:Administration, Intranasal; D000818:Animals; D015306:Biogenic Monoamines / Q000378:metabolism*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D001923:Brain Chemistry; D005260:Female; D053768:Metal Nanoparticles; D051379:Mice; D018377:Neurotransmitter Agents / Q000378:metabolism*; D013995:Time; D014025:Titanium / Q000008:administration & dosage / Q000494:pharmacology*
D015306:Biogenic Monoamines; D018377:Neurotransmitter Agents; C009495:titanium dioxide; D014025:Titanium