Hepatic and Renal Toxicity Induced by TiO₂ Nanoparticles in Rats: A Morphological and Metabonomic Study

Figure 4

Ultrastructure of hepatocytes (a, b, c) and renal proximal tubular cells (d, e, f) of animals exposed to 1 g/Kg BW (d, e) or 16 g/Kg BW (a-c, f) and sacrificed 4 days after the end of the treatment. At low magnification (a), hepatocytes showed numerous lysosomes with heterogeneous content. At higher magnification (b, c) dense nanoparticles aggregates were observed in lysosomes (arrows) and some smaller isolated aggregates were identified free in cytoplasm (arrow heads). In kidney of animals exposed to low dose (d, e), NPs aggregates of TiO₂ were very rare inside proximal tubular cells. Some isolated aggregates were identified focally in cytoplasm below the brush border (arrow heads) or in lysosomal compartment (arrow). At higher dose (f), nanoparticles aggregates are more frequent and increased in size. Aggregates were mainly localized in lysosomes (arrows) as in large vacuoles of endocytosis (white arrow).

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