Titán-dioxid nanorészecskék szubakut légúti adagolásával kiváltott elektrofiziológiai eltérések és általános toxicitás patkányban

Background and purpose: A titan-dioxid (TiO2) nanomeretű, jellemzően 100 nm-nel kisebb, reszecskei ma mar szamos, reszben kozvetlen emberi expozicioval jaro alkalmazasban megjelentek. Ismert tulajdonsagaik - nagy fajlagos felulet, szervezeten beluli mozgekonysag, oxidativ stressz keltese, gyulladasmediatorok felszabaditasa stb. - alapjan idegrendszeri karosodast okozhatnak, azonban erre vonatkozoan csak keves es ellentmondo adat all rendelkezesre. Erre, es mas femoxid-nanoreszecskekkel szerzett tapasztalatokra alapozva a jelen munkaban azt vizsgaltuk, milyen altalanos es idegrendszeri toxikus hatas idezhető elő TiO2-nanoreszecskek patkanyok legutaiba valo adagolasaval. Methods: Young adult Wistar rats (5 groups of 10 rats each) received, daily for 28 days, intratracheal instillations of titanium dioxide nanoparticles of ca. 10 nm diameter, suspended in 1% hydroxyethyl cellulose dissolved in phosphate-buffered saline, in the doses of 1, 3, and 10 mg/kg b. w. Vehicle controls received the suspension medium and there was also an untreated control group. During treatment, the rats' body weight was measured, and their clinical state observed, daily. After the 28 days, spontaneous cortical activity, sensory evoked potentials and tail nerve action potential was recorded in urethane anesthesia, then the rats were dissected and tissue samples were taken for Ti level determination and biochemical measurements of some oxidative stress indicators. Results: The two higher doses reduced the rate of body weight gain significantly. Sensory evoked potentials and tail nerve action potential were significantly slowed, but the change in the spectrum of spontaneous cortical activity was not significant. Correlation of moderate strength was found between certain evoked potential parameters and brain Ti level and oxidative stress data. Conclusion: Az eredmenyek ramutatnak a TiO2-nanoreszecskek lehetseges neurotoxicitasara, de egyben a feltetelezett hatasmechanizmus alatamasztasa celjabol vegzendő tovabbi vizsgalatok szuksegessegere is.