Animals Male Rats rat 314 article 288 nonhuman 288 male 239 controlled study 227 animal experiment 222 priority journal 195 animal tissue 140 Rats, Sprague-Dawley 137 animal cell 107 Rats, Wistar 100 Female 87 unclassified drug 85 animal model 75 female 65 animal 64 protein expression 64 Animalia 56 messenger RNA 54 Time Factors 47 RNA, Messenger 46 Humans 43 Rattus 42 metabolism 42 enzyme activity 41 Rats, Inbred Strains 38 in vitro study 37