Neurotoxicity and brain localization of europium doped Gd2O3 nanotubes in rats after intranasal instillation

• Published in: Journal of rare earths Vol. 35; no. 11; pp. 1126 - 1132
• Main Authors: Liu, Huifang, Zhao, Wencong, Wang, Xiaochun, Jia, Guang, Jin, Yi, Ge, Kun, Ma, Huanyun, Zhang, Jinchao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2017
• Subjects: Distribution; Distributionlntranasal; doped; Europium; Europium doped Gd2O3 nanotubes; Gd203; instillation; Intranasal instillation; nanotubes; Neurotoxicity; Rat; Neurotoxicity; Rat; Intranasal instillation; Europium doped Gd2O3 nanotubes; Distribution
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/j.jre.2017.05.006

Europium doped Gd203 nanotubes （Gd203：Eu3＋ NTs） were synthesized and characterized. Then, theneurotoxicity and brain localization of Gd203：Eu3＋ NTs were evaluated. All experimental rats wereadministered by intranasal instillation with 30μL Gd203：Eu3＋ NTs suspension 3.0 and 15.0 mg/mLrespectively every other day for 35 consecutive days, and the rats of control group were administeredwith an equal volume of physiological saline. The Morris water maze was used to assess the rats＇ spatiallearning and memory ability. The oxidative stress-related biomarkers and the activity of AChE in striatumand hippocampus were analyzed, and the histopathology of hippocampus and striatum was observed.The brain localization of gadolinium （Gd） was measured. The results showed that the escape latency ofthe rats in high-dose group prolonged significantly compared with that of control group after treatmentof six weeks （p 〈 0.05）, and the swimming time in D quadrant of high-dose group shortened significantlycompared with the control group （p 〈 0.01）. In addition, high-dose Gd203：Eu3＋ NTs could decrease theactivity of GSH-Px and CAT in hippocampus and the activity of SOD in striatum （p 〈 0.05）. MDA contentin hippocampus and striatum of high-dose group increased （p 〈 0.05）. High dose Gd203：Eu3＋ NTs couldincrease the activity of AChE in hippocampus （p 〈 0.05） and in striatum （p 〈 0.001）. But there were nosignificant differences between the low-dose group and control group （p 〉 0.05）. The results of Gdlocalization in brain showed that the ranking of Gd levels was olfactory bulb 〉 striatum 〉 hippocampus〉 cerebellum 〉 brain stem 〉 frontal cortex. The pathology results indicated that high dose Gd203：Eu3＋NTs resulted in degeneration necrosis, nucleus pycnosis, and axons disappearance of the nerve cells atCA1, CA3 and DG area of hippocampus. Therefore, the results implied that Gd203：Eu3＋ NTs have thepotential neurotoxicity and a possible danger in causing neurodegenerative disorders after intranasalinstillation.