animal male metabolism nonhuman Animals 240 controlled study 218 Male 216 animal experiment 178 Article 158 priority journal 156 animal tissue 142 physiology 130 mouse 120 animal cell 106 female 104 Mice 98 drug effects 92 article 86 genetics 78 protein expression 76 Female 74 unclassified drug 66 adult 62 animal model 62 rat 48 cytology 46 drug effect 46 in vitro study 46 immunohistochemistry 44 signal transduction 44