Rats 56 Rats, Wistar enzyme activity nonhuman 56 rat article 54 Animals 52 controlled study 50 animal experiment 44 animal tissue 30 priority journal 30 Female 28 animal model 27 female 24 Liver 21 male 19 Hexachlorobenzene 18 hexachlorobenzene 18 Male 17 protein expression 16 animal cell 14 uroporphyrinogen decarboxylase 14 unclassified drug 13 5 aminolevulinate synthase 12 enzyme inhibition 12 liver enzyme 11 Animalia 10 Rattus 10 Rattus norvegicus 10 oxidative stress 10