The in vitro metabolism of androgens in rat epididymis during sexual development
The in vitro activity of epididymal 5α-reductase and 3-hydroxy-steroid dehydrogenase was studied in rats during sexual development (ages 15 to 50 days). It was found that total activity (per organ) of 3-hydroxysteroid dehydrogenase reached an absolute maximum in 25 day-old rats. At this age there wa...
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| Autores principales: | , , |
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| Formato: | JOUR |
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| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00224731_v13_n10_p1207_DeLarminat |
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| Sumario: | The in vitro activity of epididymal 5α-reductase and 3-hydroxy-steroid dehydrogenase was studied in rats during sexual development (ages 15 to 50 days). It was found that total activity (per organ) of 3-hydroxysteroid dehydrogenase reached an absolute maximum in 25 day-old rats. At this age there was also a marked increase in the specific activity (per mg weight) of both enzymes studied. While at all other ages 5α-DHT was the main product from testosterone, in the 25 day-old rat, 5α-androstandiol accounted for 73% of the metabolites formed. The subcellular distribution of both enzymes in the epididymides of adult and prepuberal rats was found to present only minor differences. Kinetic parameters (KM and Vmax) were measured in the subcellular fractions of the immature epididymis. These results indicate the existence of a marked, but transient, shift in the activity of the enzymes which metabolize androgens in the epididymis, towards the formation of 5α-androstandiol during the discrete period between 20 and 30 days of life. © 1980, All rights reserved. |
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