Rats animal model article controlled study nonhuman 149 animal experiment 145 rat 143 Animals 137 priority journal 100 Female 92 female 87 animal tissue 84 Rats, Wistar 67 Male 63 Rats, Sprague-Dawley 61 animal cell 58 male 57 protein expression 42 Animalia 37 enzyme activity 33 unclassified drug 30 Disease Models, Animal 26 progesterone 24 Mice 23 Rattus 22 Liver 21 RNA, Messenger 21 Animals, Newborn 20 Hexachlorobenzene 20 Progesterone 20