animal experiment controlled study nonhuman 230 physiology Animals 226 animal 226 metabolism 156 priority journal 138 Article 132 male 124 animal tissue 122 Male 110 mouse 102 article 98 female 84 Mice 80 animal cell 72 Female 70 animal model 68 unclassified drug 66 drug effect 54 adult 52 rat 50 genetics 48 protein expression 48 drug effects 44 human 42 Humans 40 Rats 40 animal behavior 40