Rats male rat 173 Male 169 article 156 nonhuman 141 Animals 119 animal experiment 118 controlled study 115 priority journal 101 animal tissue 80 Rats, Sprague-Dawley 61 Animal 56 animal 55 animal cell 49 Rats, Wistar 48 female 48 Female 46 Support, Non-U.S. Gov't 38 metabolism 38 animal model 35 unclassified drug 30 enzyme activity 27 Rats, Inbred Strains 26 protein expression 26 drug effect 24 Animalia 23 messenger RNA 21 RNA, Messenger 20 Time Factors 20