epididymis 92 Epididymis 64 Male 62 article 58 nonhuman 58 rat 58 male 50 priority journal 48 male genital system 46 Rats 34 animal cell 34 animal experiment 34 unclassified drug 34 Spermatozoa 32 Animalia 30 androgen 28 controlled study 28 human 28 spermatozoon 28 Animal 26 Animals 26 Female 26 Support, Non-U.S. Gov't 26 fertilization 26 Fertilization 22 female 22 human cell 22 in vitro study 22 radioisotope 22 endocrine system 20