Steroid biosynthesis in the gonads of the teleost fish Jenynsia lineata
1. 1. A series of enzyme systems for steroid biosynthesis in the ovary and testis of Jenynsia lineata were demonstrated in vitro. In the ovary and testis of this teleost the following enzymic conversions of radiolabelled steroid substrates were observed in vitro: Pregnenolone → 17α-hydroxypregnenolo...
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| Autores principales: | , |
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| Publicado: |
1980
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| Acceso en línea: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03050491_v65_n4_p631_Tesone http://hdl.handle.net/20.500.12110/paper_03050491_v65_n4_p631_Tesone |
| Aporte de: |
| Sumario: | 1. 1. A series of enzyme systems for steroid biosynthesis in the ovary and testis of Jenynsia lineata were demonstrated in vitro. In the ovary and testis of this teleost the following enzymic conversions of radiolabelled steroid substrates were observed in vitro: Pregnenolone → 17α-hydroxypregnenolone plus androstenedione and testosterone and Pregnenolone → 17α-hydroxyprogesterone plus androstenedione and testosterone. 2. 2. In addition, an unusual finding in the ovary and testes was the biosynthesis of 11-deoxycortisol (compound S) from the pregnenolone and progesterone substrates and the 21-hydroxylation of progesterone to form 11-deoxycorticosterone (DOC). 3. 3. The male gonad also exhibited 11β-hydroxylase activity and testosterone was converted to 11β-hydroxyandrostenedione. 4. 4. All conversions of radiolabelled substrates were identified on the basis of reverse isotope dilution and crystallization to constant specific activity. 5. 5. The physiological significance of DOC and 11β-hydroxyandrostenedione biosynthesis in the gonads of Jenynsia lineata and its possible role in the reproductive process are viewed against similar findings in other fishes. © 1980. |
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