Hepatic transcriptomic alterations for N,N-dimethyl-p-toluidine (DMPT) and p-toluidine after 5-day exposure in rats

To identify liver transcripts differentially expressed due to treatment with N, N-dimethyl-p-toluidine (DMPT) and p-toluidine, we collected RNA during the from male F344/N rats exposed to 0, 1, 6, 20, 60 or 120 mg/kg DMPT (or p-toluidine), 5 days after exposure for animals 5-6 weeks of age. These samples were interrogated with the Affymetrix Rat Genome 230 2.0 GeneChip Array. A total of 511 gene transcripts were differentially expressed due to DMPT treatment and 354 gene transcripts were differentially expressed due to p-toluidine treatment (false discovery rate (FDR) < 0.05). There were 6 groups and 5x replication for each group for each chemical, for 60 total samples. The groups were (1) DMPT-0mg/kg, (2) DMPT-1mg/kg, (3) DMPT-6mg/kg, DMPT-20mg/kg, DMPT-60mg/kg, DMPT-120mg/kg, ptoluidine-0mg/kg, ptoluidine-1mg/kg, ptoluidine-6mg/kg, ptoluidine-20mg/kg, ptoluidine-60mg/kg, ptoluidine-120mg/kg. We compared vehicle control (0mg/kg) vs dose within each chemical using ORIOGEN software. The permutation based p-values for each test were significant for FDR≤5%.