Session: SAT 358-380-Steroid Hormone Biosynthesis & Metabolism
Poster Board SAT-373
We established a GC-MS/MS method for the measurement of serum testosterone (T), dihydrotestosterone (DHT), estradiol (E2), estrone (E1), DHEA, A, and progesterone (P). After addition of isotope-labeled standards, steroids were extracted to chlorobutane, purified on a silica-column and derivatized using pentafluorobenzyl hydroxylamine hydrochloride followed by pentafluorobenzoyl chloride. Steroids were analyzed in MRM-mode with ammonia as reagent gas.
The lower limits of quantification (LLOQ) for T, DHT, E2, E1, DHEA, A, and P were 25, 5, 2, 2, 50, 12, and 50 pg/ml, respectively. The serum levels of all these sex steroids, except T and E1, were above the LLOQ when analyzed in ≥250 µl female mouse serum (average levels: T 14, DHT 13, E2 2.4, E1 0.5, DHEA 163, A 189, and P 13912 pg/ml). E2 and E1 were undetectable in male serum but all other sex steroids were reliably measured using 100 µl of male mouse serum (average levels: T 8235, DHT 168, DHEA 149, A 207, and P 680 pg/ml). As expected, orchidectomy (orx) resulted in a dramatic reduction of T, DHT and A. In contrast, serum P was substantially increased in orx mice (+404%, p<0.01) and E2 treatment of orx mice normalized serum P, suggesting that testicle-derived T is involved in the regulation of circulating levels of adrenal-derived P via an estrogenic mechanism in male mice.
In conclusion, our developed GC-MS/MS-based methodology for the measurement of a comprehensive serum sex steroid profile in mice might be useful for the characterization of sex steroid metabolism in a variety of sex-steroid related transgenic mouse models.
Nothing to Disclose: MEN, LV, T, AKN, HR, CO
*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm
See more of: Abstracts - Orals, Featured Poster Presentations, and Posters