Serum androgen levels in senescent Cr1:CD-1 (ICR)BR mice: effects of castration and testosterone treatment.

Serum levels of dehydroepiandrosterone, androstenedione, testosterone, and dihydrotestosterone were measured in intact, orchiectomized and orchiectomized-androgen-treated CD-1 mice. Although dehydroepiandrosterone was not detectable in the serum of old mice, approximately half of the very substantial serum concentration of this hormone found in the mature mice appeared to be of adrenal origin. In contrast to dehydroepiandrosterone, serum levels of testosterone and, when detectable, the other androgens, were the same in mature and senescent intact males. Serum levels responded similarly to castration and testosterone replacement. Seminal vesicle weights reflected the similar serum androgen levels found in both age groups. The results indicate that there is neither an age-associated decline in the serum concentration of testosterone nor an apparent alteration in the hepatic and/or peripheral metabolism of testosterone in aging CD-1 male mice.