Steroid dynamics in the rabbit
Male rabbits were infused at a constant rate with /sup 3/H-androstenedione//sup 14/C-estrone (n . 5) or /sup 3/H-testosterone//sup 14/C-estradiol-17 beta (n . 3) for 3 1/2 hr and blood samples were obtained over the last hour and analyzed for radioactivity as androstenedione (A), testosterone (T), estrone (E1), estradiol-17 beta (E2 beta) and estradiol-17 alpha (E2 alpha). The mean value for the metabolic clearance rate of androstenedione (MCRA) was 85 +/- 10 l/day/kg, which was significantly greater than the mean MCRE1 59 +/- 10 l/day/kg. MCRT, 42 +/- 8 l/day/kg, and MCRE2 beta, 45 +/- 9 l/day/kg were not different. The conversion ratio of androstenedione to testosterone (CRA,T) was greater than CRT,A but for the estrogens, CRE2 beta, E1 was greater than CRE1,E2 beta. CRE2 beta, E2 alpha was greater than CRE1,E2 alpha. The overall aromatization of androstenedione to estrone, the fraction of /sup 3/H-androstenedione infused into the blood and measured as /sup 3/H-estrone in blood (( rho)A,E1BB) was 0.0005 +/- 0.0001 and for (rho)T,E2 beta BB was 0.0012 +/- 0.0006. In the rabbit both sex hormone binding globulin (SHBG) and albumin binding may effect the MCRs, and peripheral aromatization of androgens occurs to a far lesser degree than in humans and primates.
- Research Organization:
- Univ. of Massachusetts Medical Center, Worcester
- OSTI ID:
- 5655724
- Journal Information:
- Steroids; (United States), Vol. 43:2
- Country of Publication:
- United States
- Language:
- English
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ANDROSTENEDIONE
METABOLISM
ESTRADIOL
ESTRONE
TESTOSTERONE
ALBUMINS
AROMATIZATION
BLOOD
CARBON 14 COMPOUNDS
CHEMICAL BONDS
CLEARANCE
GLOBULINS
RABBITS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANDROGENS
ANDROSTANES
ANIMALS
BIOLOGICAL MATERIALS
BODY FLUIDS
CHEMICAL REACTIONS
ESTRANES
ESTROGENS
HORMONES
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KETONES
LABELLED COMPOUNDS
MAMMALS
MATERIALS
ORGANIC COMPOUNDS
PROTEINS
STEROID HORMONES
STEROIDS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques