Fig. 6

Results of microarray and Quantitative real-time polymerase chain reaction Quantitative real-time polymerase chain reaction (qRT-PCR) on genes that were highly expressed in the microarray analysis in lung tissue after inhalation exposure of polypropylene. Clustered heatmaps showing the expression patterns based on mRNA whose expression ratio is more than twice that of the control among genes whose expression level is above the median value in inhalation exposure (A) and intratracheal instillation (B), respectively. qRT-PCR in lung tissue in inhalation exposure (C). Red and blue represent high and low expression in each exposure group, and color density indicating levels of fold change was displayed in the heatmaps. Persistent increases of genes at 1–6 months after exposure in the high-concentration group in qRT-PCR analysis. Data are presented as mean ± SD for n = 5/group (*p < 0.05, **p < 0.01)