Fig. 8. A-H. Immunohistochemical analysis of the heart tissue sections for the detection of nuclear factor erythroid-derived 2-like 2 (Nrf2) and glutathione peroxidase in rats intratracheally instilled with either saline (control) or cerium oxide nanoparticles (CNPs), with or without cisplatin (CDDP) administration. (A) Representative heart section obtained from saline-treated rats showing normal heart with Nrf2 nuclear staining of few cardiomyocytes (arrow). (B) Representative heart section obtained from saline-treated rats showing normal heart with glutathione peroxidase cytoplasmic staining of few cardiomyocytes (arrow). (C) Representative heart section obtained from CDDP + saline-treated rats showing increased number of nuclei of cardiomyocytes stained with Nrf2 (arrow). (D) Representative heart section obtained from CDDP + saline-treated rats showing increased number of cardiomyocytes stained with glutathione peroxidase (arrow). (E) Representative heart section obtained from CNPs-treated rats showing increased number of nuclei of cardiomyocytes stained with Nrf2 (arrow). (F) Representative heart section obtained from CNPs-treated rats showing increased number of cardiomyocytes stained with glutathione peroxidase (arrow). (G) Representative heart section obtained from CDDP + CNPs-treated rats showing increased number of nuclei of cardiomyocytes stained with Nrf2 (arrow). (H) Representative heart section obtained from CDDP + CNPs-treated rats showing increased number of cardiomyocytes stained with glutathione peroxidase (arrow). (I) Quantitative evaluation of Nrf2 nuclear staining of cardiomyocytes of hearts obtained from rats intratracheally instilled with either saline (control) or cerium oxide nanoparticles (CNPs), with or without cisplatin (CDDP) administration (n=8). (J) Quantitative evaluation of glutathione peroxidase staining of cardiomyocytes of hearts obtained from rats intratracheally instilled with either saline or CNPs, with or without CDDP administration (n=7-8). Scale bars: 50 µm.