animal animal experiment male nonhuman 280 Animals 270 Male 262 controlled study 238 Article 194 metabolism 183 priority journal 169 physiology 146 animal tissue 136 mouse 123 female 122 Mice 107 animal cell 100 article 100 Female 96 drug effects 94 adult 90 animal model 83 genetics 73 rat 70 drug effect 69 unclassified drug 68 protein expression 64 human 60 Rats 58 Humans 54 in vitro study 50