Rats rat 673 nonhuman 522 article 469 Animals 416 animal experiment 391 priority journal 356 Animal 322 controlled study 321 Male 315 Female 300 animal cell 264 Support, Non-U.S. Gov't 208 female 193 animal tissue 178 Rats, Sprague-Dawley 177 animal 177 male 175 Rats, Inbred Strains 160 metabolism 130 endocrine system 110 unclassified drug 110 Rats, Wistar 104 in vitro study 103 radioisotope 103 Animalia 101 animal model 101 protein expression 83 Liver 78 Kinetics 76