title: Sexual behavior and testosterone in middle-aged male rats.
mesh_terms: D000375:Aging; D000818:Animals; D004542:Ejaculation; D008297:Male; D051381:Rats; D012661:Semen / Q000378:metabolism; D012726:Sexual Behavior, Animal; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone