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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
09/06/2017 |
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Data da última atualização: |
09/06/2017 |
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Autoria: |
MORI, M.; MATSUKURA, S.; KAWAKURA, K.; TAMAOKI, B.-I. |
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Título: |
In-vitro synthesis of androgen from pregnenolone in the testes of the goat (Capra hircus) and identification of 5-pregnene-3beta,17alpha,20alpha-triol as an intermediate in the metabolic pathway of pregnenolone. |
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Ano de publicação: |
1980 |
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Fonte/Imprenta: |
Journal of Endocrinology, v. 84, n. 2, p. 381-390, Feb. 1980. |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: When [4(-14)C]pregnenolone was aerobically incubated in vitro in the presence of NAD+ and NADPH with cell-free homogenates of testicular tissue of adult domestic goats (Capra hircus), progesterone, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 17alpha,20alpha-dihydroxy-4-pregnen-3-one, dehydroepiandrosterone, androstenedione and testosterone were identified as its known metabolites. Time-course studies on this metabolism showed that the production of 17alpha,20alpha-dihydroxy-4-pregnen-3-one and testosterone constantly increased up to the end of incubation, suggesting that these are both end-products of pregnenolone metabolism in this system. The other metabolites behaved as intermediates and were ultimately converted, in part, to testosterone by the testicular homogenates, indicating that testosterone was synthesized through both 4-ene and 5-ene-pathways. Furthermore, besides these metabolites, 5-pregnene-3beta,17alpha,20alpha-triol was also identified as an intermediary metabolite, formed from pregnenolone through 17alpha-hydroxypregnenolone in the presence of NADPH, and further convertible into 17alpha,20alpha-dihydroxy-4-pregnen-3-one by the microsomal fraction and into 17alpha-hydroxypregnenolone by the cytosol fraction in the presence of NAD+ and NADP+. It was not, however, significantly transformed into C19-steroids. Furthermore, 17alpha,20alpha-dihydroxy-4-pregnen-3-one, which was formed either from 5-pregnene-3beta,17alpha,20alpha-triol or from 17alpha-hydroxyprogesterone, remained almost unchanged without conversion to C19-steroids when incubated with the caprine testicular homogenates. MenosAbstract: When [4(-14)C]pregnenolone was aerobically incubated in vitro in the presence of NAD+ and NADPH with cell-free homogenates of testicular tissue of adult domestic goats (Capra hircus), progesterone, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 17alpha,20alpha-dihydroxy-4-pregnen-3-one, dehydroepiandrosterone, androstenedione and testosterone were identified as its known metabolites. Time-course studies on this metabolism showed that the production of 17alpha,20alpha-dihydroxy-4-pregnen-3-one and testosterone constantly increased up to the end of incubation, suggesting that these are both end-products of pregnenolone metabolism in this system. The other metabolites behaved as intermediates and were ultimately converted, in part, to testosterone by the testicular homogenates, indicating that testosterone was synthesized through both 4-ene and 5-ene-pathways. Furthermore, besides these metabolites, 5-pregnene-3beta,17alpha,20alpha-triol was also identified as an intermediary metabolite, formed from pregnenolone through 17alpha-hydroxypregnenolone in the presence of NADPH, and further convertible into 17alpha,20alpha-dihydroxy-4-pregnen-3-one by the microsomal fraction and into 17alpha-hydroxypregnenolone by the cytosol fraction in the presence of NAD+ and NADP+. It was not, however, significantly transformed into C19-steroids. Furthermore, 17alpha,20alpha-dihydroxy-4-pregnen-3-one, which was formed either from 5-pregnene-3beta,17alpha,20alpha-triol or from... Mostrar Tudo |
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Palavras-Chave: |
17-alpha-Hydroxypregnenolone; 20-Hydroxysteroid Dehydrogenases; 3-Hydroxysteroid Dehydrogenases. |
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Thesaurus Nal: |
Androgens; Androstenedione; Biosynthesis; Goats; pregnenolone; Progesterone; Testosterone. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02564naa a2200277 a 4500
001 2070660
005 2017-06-09
008 1980 bl uuuu u00u1 u #d
100 1 $aMORI, M.
245 $aIn-vitro synthesis of androgen from pregnenolone in the testes of the goat (Capra hircus) and identification of 5-pregnene-3beta,17alpha,20alpha-triol as an intermediate in the metabolic pathway of pregnenolone.
260 $c1980
520 $aAbstract: When [4(-14)C]pregnenolone was aerobically incubated in vitro in the presence of NAD+ and NADPH with cell-free homogenates of testicular tissue of adult domestic goats (Capra hircus), progesterone, 17alpha-hydroxypregnenolone, 17alpha-hydroxyprogesterone, 17alpha,20alpha-dihydroxy-4-pregnen-3-one, dehydroepiandrosterone, androstenedione and testosterone were identified as its known metabolites. Time-course studies on this metabolism showed that the production of 17alpha,20alpha-dihydroxy-4-pregnen-3-one and testosterone constantly increased up to the end of incubation, suggesting that these are both end-products of pregnenolone metabolism in this system. The other metabolites behaved as intermediates and were ultimately converted, in part, to testosterone by the testicular homogenates, indicating that testosterone was synthesized through both 4-ene and 5-ene-pathways. Furthermore, besides these metabolites, 5-pregnene-3beta,17alpha,20alpha-triol was also identified as an intermediary metabolite, formed from pregnenolone through 17alpha-hydroxypregnenolone in the presence of NADPH, and further convertible into 17alpha,20alpha-dihydroxy-4-pregnen-3-one by the microsomal fraction and into 17alpha-hydroxypregnenolone by the cytosol fraction in the presence of NAD+ and NADP+. It was not, however, significantly transformed into C19-steroids. Furthermore, 17alpha,20alpha-dihydroxy-4-pregnen-3-one, which was formed either from 5-pregnene-3beta,17alpha,20alpha-triol or from 17alpha-hydroxyprogesterone, remained almost unchanged without conversion to C19-steroids when incubated with the caprine testicular homogenates.
650 $aAndrogens
650 $aAndrostenedione
650 $aBiosynthesis
650 $aGoats
650 $apregnenolone
650 $aProgesterone
650 $aTestosterone
653 $a17-alpha-Hydroxypregnenolone
653 $a20-Hydroxysteroid Dehydrogenases
653 $a3-Hydroxysteroid Dehydrogenases
700 1 $aMATSUKURA, S.
700 1 $aKAWAKURA, K.
700 1 $aTAMAOKI, B.-I.
773 $tJournal of Endocrinology$gv. 84, n. 2, p. 381-390, Feb. 1980.
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Embrapa Caprinos e Ovinos (CNPC) |
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