Biotransformation of all-trans-retinol and all-trans-retinal to all-trans-retinoic acid in rat conceptal homogenates

Chen, Hao; Namkung, Moses J.; Juchau, Mont R.

doi:10.1016/0006-2952(95)02005-w

Cited by 47 publications

(29 citation statements)

References 23 publications

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“…The third major activity was associated with aldehyde oxidase as previously observed by Chen and Juchau (40) in rat conceptual homogenates. This enzyme could be easily separated from dehydrogenases by chromatography on CM-Sephadex.…”

Section: Discussionsupporting

confidence: 55%

Metabolism of Retinaldehyde and Other Aldehydes in Soluble Extracts of Human Liver and Kidney

Ambroziak

Izaguirre

Pietruszko

1999

Journal of Biological Chemistry

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Purification and characterization of enzymes metabolizing retinaldehyde, propionaldehyde, and octanaldehyde from four human livers and three kidneys were done to identify enzymes metabolizing retinaldehyde and their relationship to enzymes metabolizing other aldehydes. The tissue fractionation patterns from human liver and kidney were the same, indicating presence of the same enzymes in human liver and kidney. Moreover, in both organs the major NAD ؉ -dependent retinaldehyde activity copurified with the propionaldehyde and octanaldehyde activities; in both organs the major NAD ؉ -dependent retinaldehyde activity was associated with the E1 isozyme (coded for by aldh1 gene) of human aldehyde dehydrogenase. A small amount of NAD ؉ -dependent retinaldehyde activity was associated with the E2 isozyme (product of aldh2 gene) of aldehyde dehydrogenase. Some NAD ؉ -independent retinaldehyde activity in both organs was associated with aldehyde oxidase, which could be easily separated from dehydrogenases. Employing cellular retinoid-binding protein (CRBP), purified from human liver, demonstrated that E1 isozyme (but not E2 isozyme) could utilize CRBPbound retinaldehyde as substrate, a feature thought to be specific to retinaldehyde dehydrogenases. This is the first report of CRBP-bound retinaldehyde functioning as substrate for aldehyde dehydrogenase of broad substrate specificity. Thus, it is concluded that in the human organism, retinaldehyde dehydrogenase (coded for by raldH1 gene) and broad substrate specificity E1 (a member of EC 1.2.1.3 aldehyde dehydrogenase family) are the same enzyme. These results suggest that the E1 isozyme may be more important to alcoholism than the acetaldehyde-metabolizing enzyme, E2, because competition between acetaldehyde and retinaldehyde could result in abnormalities associated with vitamin A metabolism and alcoholism.In mammalian organisms retinoids and their derivatives are important in regulation of diverse physiological functions. Retinoic acid has only recently been recognized as a major hormone in cell differentiation and development (1, 2). It is also thought to be a causative agent in diseases such as cancer (3) and more recently, schizophrenia (4). In mammals, biosynthesis of retinoids proceeds via central or excentric cleavage of carotene to retinaldehyde followed by its reduction to retinol or oxidation to retinoic acid (5-7).Enzymes with broad substrate specificity such as alcohol and aldehyde dehydrogenases have been known for a long time to include retinaldehyde among their many substrates (8 -10). Efforts have been also made to identify aldehyde dehydrogenase isozyme active with retinaldehyde (11-13). The mouse enzymes were found to have activity (11) as well as the human E1 isozyme (12, 13). However, more recently, cytosolic NAD ϩ -linked retinaldehyde dehydrogenases, more specific toward alltrans-retinaldehyde and assumed to be distinct from aldehyde dehydrogenase of broad substrate specificity, have been purified from rat liver (Ref. 14, retinaldehyde dehydrogenase 1)...

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Section: Discussionsupporting

confidence: 55%

Metabolism of Retinaldehyde and Other Aldehydes in Soluble Extracts of Human Liver and Kidney

Ambroziak

Izaguirre

Pietruszko

1999

Journal of Biological Chemistry

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“…Testicular RA is synthesized in a two-step process from Rol provided either by the circulation or by the local stores of retinyl esters. The initial step, conversion of Rol into Ral, is the rate-limiting and reversible step in RA synthesis (40). We found that Rdh10 is expressed in both mouse Sertoli cells and spermatogonia.…”

Section: Discussionmentioning

confidence: 82%

Retinol dehydrogenase 10 is indispensible for spermatogenesis in juvenile males

Tong

Yang

Davis

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

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Retinoic acid (RA), an active vitamin A derivative, is essential for mammalian spermatogenesis. Genetic studies have revealed that oxidation of vitamin A to retinal by retinol dehydrogenase 10 (RDH10) is critical for embryonic RA biosynthesis. However, physiological roles of RDH10 in postnatal RA synthesis remain unclear, given that Rdh10 loss-of-function mutations lead to early embryonic lethality. We conducted in vivo genetic studies of Rdh10 in postnatal mouse testes and found that an RDH10 deficiency in Sertoli cells, but not in germ cells, results in a mild germ cell depletion phenotype. A deficiency of RDH10 in both Sertoli and germ cells in juvenile mice results in a blockage of spermatogonial differentiation, similar to that seen in vitamin A-deficient animals. This defect in spermatogenesis arises from a complete deficiency in juvenile testicular RA synthesis and can be rescued by retinoid administration. Thus, in juvenile mice, the primary, but not exclusive, source of RA in the testes is Sertoli cells. In contrast, adult Rdh10 -deficient mice exhibit phenotypically normal spermatogenesis, indicating that during development a change occurs in either the cellular source of RA or the retinaldehyde dehydrogenase involved in RA synthesis.

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“…Several isoforms of retinoic acid are generated by conversion of retinol to retinal by alcohol dehydrogenase enzymes and then to retinoic acids by the activity of aldehyde dehydrogenases (Duester, 1996). The rate limiting step for retinoic acid formation is determined by the activity of retinol dehydrogenase (Chen et al, 1995). Retinoic acids are potent morphogens that provide axial patterning information in developing vertebrates (Means and Gudas, 1995).…”

Section: Vitamin a And Early Developmentmentioning

confidence: 99%

Vitamins A and E in the maternal diet influence egg quality and early life stage development in fish: a review

Palace¹,

Werner²

2006

Sci. Mar.

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SUMMARY: Early development in fish is dependent on essential nutrients present in the egg. Vitamins E and A are critical to the normal development of fish embryos. Vitamin E functions primarily as an antioxidant to protect unsaturated lipids from oxidative degradation. Vitamin A or its provitamin carotenoid forms support growth, are required for the differentiation and maintenance of epithelial tissue and can be converted to forms of the vitamin that are potent morphogens. Fish cannot synthesise either of the vitamins, so the maternal dietary content of each prior to oogenesis is an important determinant of reproductive fitness. Here we review the basic metabolism of vitamins E and A and carotenoids and their processing from the maternal diet and deposition into eggs. Evidence for the link between levels of each of the vitamins in eggs and measures of reproductive fitness are also discussed. -El desarrollo embrionario en peces es dependiente de los nutrientes esenciales presentes en el huevo. Las vitaminas E y A son críticas en el desarrollo normal de los embriones de los peces. La vitamina E funciona sobre todo como un antioxidante para proteger los lípidos no saturados contra la degradación oxidativa. La vitamina A, o los carotenoides formas de provitamina, se requieren para la diferenciación y el mantenimiento del tejido fino epitelial y se puede convertir a las formas de la vitamina que son morfogenes potentes. Los peces tampoco pueden sintetizar las vitaminas, de modo que el contenido dietético materno de cada una antes de la oogenesis es un determinante importante de la aptitud reproductiva. Aquí repasamos el metabolismo básico de las vitaminas E y A y los carotenoides y su procesamiento desde la dieta materna a la deposición en los huevos. Se discute también la evidencia del acoplamiento entre los niveles de cada una de las vitaminas en los huevos y las medidas de aptitud reproductiva en los adultos.

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Biotransformation of all-trans-retinol and all-trans-retinal to all-trans-retinoic acid in rat conceptal homogenates

Cited by 47 publications

References 23 publications

Metabolism of Retinaldehyde and Other Aldehydes in Soluble Extracts of Human Liver and Kidney

Metabolism of Retinaldehyde and Other Aldehydes in Soluble Extracts of Human Liver and Kidney

Retinol dehydrogenase 10 is indispensible for spermatogenesis in juvenile males

Vitamins A and E in the maternal diet influence egg quality and early life stage development in fish: a review

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