Epilepsy, the third most common neurological disorder, is characterized by recurrent unprovoked seizures. Although the mechanisms of epileptic convulsions have been a subject of intensive investigations for many years in most cases the etiology of the disease is not known [1].Metallic elements participating in the processes like: oxidative stress, excitotoxicity, mitochondrial dysfunction or protein aggregation may lead to the atrophy and death of neurons in case of some neurodegenerative disorders [2][3][4]. Because epileptic seizures induce neurodegeneration in selected areas of brain it is suspected that metals may be involved in the pathogenesis and progress of epilepsy as well [5].Existing evidence suggests that epileptic seizures significantly change metabolism and distribution of trace elements in the nervous tissue [6][7][8]. From the other hand, content of metals determinates susceptibility to convulsions [9].In our experiment we used pilocarpine in order to induce epilepsy in rats. In order to find what elements are involved in the pathogenesis and progress of epileptic convulsions the comparison between pilocarpine treated and control rats was done. The samples of rat brain were cut using a cryomicrotome into 15 µm thick slices. Thin tissue sections were mounted on Ultralene foil and freeze-dried.X-ray fluorescence microscopy was employed for topographic and quantitative analysis of selected metals in the areas of brain tissue involved in epilepsy. The measurements were done on the bending magnet beamline L at HASYLAB. The multilayer monochromator was applied and the primary photon energy was set to 17 keV. The beam was focused with polycapillary optics for a final beam spot dimension of 15 µm x 15 µm. The characteristic X-ray lines were measured using the Vortex SDD detector from SII Nano Technology USA inc. and the time of spectra acquisition was equal to 6 s per pixel. Measurements of NIST standard reference materials (SRM 1833 and SRM 1832) were performed for spectrometer calibration.The elements such us P, S, Cl, K, Ca, Fe, Cu, Zn, Br, Rb and Sr were detected in rat brain sections. For each sample two-dimensional analysis of elemental distribution was performed for the area of hippocampus and brain cortex. The results of such analysis for selected control and epileptic sample were shown in Figures 1 and 2 respectively.For four regions of hippacampus formation (CA1 -Cornu Ammonis, CA3, DG -Dentate Gyrus and H -Hilus) and motor cortex the mean masses per unit area were evaluated. The areas taken into account in calculations were equal to 300 µm per 300 µm. The preliminary results showed that the level of Ca tends to be higher for CA1 region of hippocampus and cortex in case of animals with pilocarpine induced epilepsy. The opposite relation was observed for Zn level in the area of DG.1551

The main goal of this study was to evaluate in vivo effects of low dose of PEG-coated magnetic iron oxide nanoparticles (IONPs) on the rat liver. The IONPs was intravenously injected into rats at a dose equaled to 0.03 mg of Fe per 1 kg of an animal body weight. The elemental composition of liver tissue in rats subjected to IONPs action and controls were compared. Moreover, in order to determine the dynamics of nanoparticles (NPs) induced elemental changes, the tissues taken from animals 2 hours, 24 hours, and 7 days from IONPs injection were examined. The analysis of subtle elemental anomalies occurring as a result of IONPs action required application of highly sensitive analytical method. The total reflection X-ray fluorescence spectroscopy perfectly meets such requirements and therefore it was used in this study. The obtained results showed increasing trend of Fe level within liver occurring 2 hours from IONPs injection. One day after NPs administration, the liver Fe content presented the baseline level what suggests only the short-term accumulation of nanoparticles in the organ. The Ca, Cu, and Zn levels changed significantly as a result of NPs action. Moreover, the anomalies in their accumulation were still observed 7 days after IONPs injection. The level of Cu decreased while those of Ca and Zn increased in the liver of NPs-treated animals. The reduced liver Cu, followed by elevated serum level of this element, might be related in triggering the mechanisms responsible for Fe metabolism in the organism.

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The main goal of this study was to evaluate the elemental changes occurring in the main rat organs (kidneys, spleen, heart, brain) as a result of polyethylene glycol-coated magnetic iron oxide nanoparticles (PEG-IONPs) administration. For this purpose, 24 animals were divided into four equinumerous groups, and the three of them were intravenously injected with PEG-IONPs dispersed in 15% solution of mannitol in dose of 0.03 mg of Fe per 1 kg of body weight. The organs were collected 2 h, 24 h and 7 days passing from NPs administration, respectively, for the 2H, 24H, and 7D experimental groups. The forth group of animals, namely control group, was injected with 1 mL of physiological saline solution. For the analysis of subtle elemental changes occurring in the organs after nanoparticles injection, highly sensitive method of total reflection X-ray fluorescence spectroscopy was used. Obtained results showed that administration of even such low doses of PEG-IONPs may lead to statistically significant changes in the accumulation of selected elements within kidneys and heart. Two hours and 7 days from NPs injection, the Fe level in kidneys was higher compared to that of control rats. Elevated levels of Cu, possibly associated with systemic action of ceruloplasmine enzyme, were found within kidneys in 24H and 7D groups, while in heart the similar observation was done only for 24H group. The levels of Ca and Zn increased in kidneys and heart during the first 2 h from the injection and were again elevated in these organs 7 days later. The abnormalities in Ca and Zn accumulations occurring exactly in the same manner may suggest that these elements may interplay either in the mechanisms responsible for the detoxification of the PEG-IONPs or pathological processes occurring as a result of their action.

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