controlled study male nonhuman article 436 animal experiment 424 Animals 418 priority journal 410 Male 394 animal tissue 299 female 239 mouse 213 animal cell 211 animal model 174 animal 168 rat 167 Mice 158 Article 151 Female 150 protein expression 124 Rats 113 metabolism 108 unclassified drug 101 physiology 88 adult 85 enzyme activity 84 human 83 Animalia 71 Humans 69 drug effect 60 in vitro study 59