title: Age-related changes in serum and brain levels of androgens in male Brown Norway rats.
abstract: Age-related depletion of androgens in men results in functional impairments in androgen-responsive tissues, such as the brain, resulting in increased risk for Alzheimer's disease. To investigate the relationship between normal age-related hormone loss and Alzheimer's disease risk, we evaluated the brain and serum levels of androgens and estrogen in aging male rats. We observed that increasing age was associated with a significant reduction in brain levels of the potent androgen dihydrotestosterone and a trend toward decreased testosterone. Brain levels of soluble beta-amyloid were observed to increase with age. Collectively, these findings highlight differences in brain and circulating levels of androgens during aging, and identify an inverse correlation with beta-amyloid levels that may be relevant to Alzheimer's disease risk.
authors.affiliation: Neuroscience Graduate Program, Keck School of Medicine, University of Southern California, Los Angeles, California, USA.
authors.forename: Emily R
authors.initials: ER
authors.lastname: Rosario
authors.forename: Lilly
authors.initials: L
authors.lastname: Chang
authors.forename: Tina L
authors.initials: TL
authors.lastname: Beckett
authors.forename: Jenna C
authors.initials: JC
authors.lastname: Carroll
authors.forename: M
authors.initials: M
authors.lastname: Paul Murphy
authors.forename: Frank Z
authors.initials: FZ
authors.lastname: Stanczyk
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Pike
mesh_terms: D000375:Aging / Q000378:metabolism*; D000544:Alzheimer Disease / Q000097:blood* / Q000503:physiopathology; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000728:Androgens / Q000032:analysis / Q000097:blood*; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000503:physiopathology; D013196:Dihydrotestosterone / Q000097:blood; D015536:Down-Regulation / Q000502:physiology; D008297:Male; D058225:Plaque, Amyloid / Q000378:metabolism; D051381:Rats; D012307:Risk Factors; D013739:Testosterone / Q000097:blood; D015854:Up-Regulation / Q000502:physiology
chemical_list: D016229:Amyloid beta-Peptides; D000728:Androgens; D013196:Dihydrotestosterone; D013739:Testosterone