Male animal 86 male 86 metabolism rat Rats 78 article 70 Animals 50 animal experiment 46 nonhuman 42 Animal 38 controlled study 32 drug effect 31 priority journal 24 enzymology 23 in vitro study 22 unclassified drug 22 animal cell 21 Rats, Inbred Strains 20 Rats, Wistar 20 Support, Non-U.S. Gov't 20 Wistar rat 20 animal tissue 20 rat strain 20 physiology 19 radioisotope 16 Liver 15 liver 15 Article 14 Rats, Sprague-Dawley 14