animal model article controlled study rat nonhuman 176 animal experiment 168 Rats 143 Animals 133 priority journal 123 female 100 animal tissue 96 Female 88 male 71 Rats, Wistar 67 animal cell 64 Male 61 Rats, Sprague-Dawley 55 protein expression 51 enzyme activity 39 Animalia 33 unclassified drug 30 progesterone 29 Disease Models, Animal 26 Hexachlorobenzene 26 hexachlorobenzene 26 Rattus 24 Liver 23 Mice 23 immunohistochemistry 23 Progesterone 22