19682
Compared with normally - fed counterparts , PM - CP rats exhibited higher glutathione S - transferase , aminopeptidase N and cysteine S - conjugate beta - lyase ( CCBL ) and lower gamma - glutamyltransferase activities , PM - FU rats exhibited decreased dihydropyrimidine dehydrogenase and cytochrome P450 1A1 / 2 activities and PM - MMC rats showed higher quinone reductase and depleted xanthine oxidase activities .
 glutathione, S, N, cysteine, S, dihydropyrimidine, MMC, quinone, xanthine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 glutathione, S, N, cysteine, S, dihydropyrimidine, MMC, quinone, xanthine