controlled study male metabolism nonhuman 221 Animals 217 animal 217 Male 216 Article 172 animal experiment 171 priority journal 163 animal tissue 132 female 126 mouse 117 physiology 114 drug effects 101 animal cell 98 Mice 91 Female 90 adult 85 article 84 genetics 84 human 77 protein expression 77 Humans 73 animal model 66 unclassified drug 63 pathology 57 in vitro study 53 signal transduction 48 drug effect 47