Pregnenolone, dehydroepiandrosterone, and their sulfate and fatty acid esters in the rat brain

Jo, D; Abdallah, Malika Aït; Young, Jacques; Baulieu, Étienne-Émile; Röbel, P

doi:10.1016/0039-128x(89)90003-2

Cited by 113 publications

(66 citation statements)

References 10 publications

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“…A high activity of acyl transferase catalyzing the synthesis of steroid fatty acid esters was found in brain microsomes of young male rats (55). These known lipoidal steroid conjugates have been found in several tissues (54,56), and several authors have suggested that C 21 , C 19 , and C 18 steroids linked to fatty acids via hydroxyl functions at positions C-3, C-17, and C-21 are sequestered in tissues in which the unconjugated steroid can be released by the action of intracellular esterases (57). Furthermore, these esters of PREG, DHEA, androst-5-ene-3␤,17␤-diol, and estradiol can be formed in plasma of several mammalian species (58,59).…”

Section: Structural Identification: Some Hypothesesmentioning

confidence: 98%

“…These experiments were performed with a homogenate of rat brain in a Tris hypotonic buffer (pH by guest, on March 22, 2019 www.jlr.org Downloaded from 7.4). Aliquots of ‫ف‬ 300 mg of homogenate were incubated with [ 3 H]PREG for 1, 4, and 48 h at 37 Њ C. Control experiments were carried out by incubating [ 3 H]PREG with a boiled homogenate for 4 h and in the absence of rat brain homogenate.…”

Section: Extractionmentioning

confidence: 99%

“…The MeOH/CHCl 3 (1:1) fraction from the SPE containing lipoidal steroids was derivatized with HFBA or TEA/HFBA. The reaction with HFBA was performed as de- by guest, on March 22, 2019 www.jlr.org Downloaded from scribed above for sulfated and free steroids except that the temperature was kept at 70 Њ C. Concerning the reaction with TEA/ HFBA, the residue was dissolved in 100 l of acetone, 20 l of TEA and 20 l of HFBA were added, and the mixture was heated for 30 min at 70 Њ C. This reaction has been optimized according to several parameters, such as the relative amount of reagent, reaction duration, and temperature. A liquid-liquid partition step between water and hexane was performed.…”

Section: Derivatization Reactionmentioning

confidence: 99%

“…by guest, on March 22, 2019 www.jlr.org Downloaded from SPE, only 17% of the radioactivity was recovered in the organic phase after the solvolysis step (ethyl acetate extraction) and 83% remained in the aqueous phase. This latter fraction contained unhydrolyzed [ 3 H]PREG-S.…”

Section: Analysis Of Preg-s and Dhea-s By Gc-ms: Improvement In Samplmentioning

confidence: 99%

“…Until now, PREG and DHEA have been identified in rat brain as unconjugated steroids and steroids released either by solvolysis (sulfate esters) or by saponification (fatty acid esters). Relatively large amounts of fatty acid esters of PREG were measured in rat brain (22,54). A high activity of acyl transferase catalyzing the synthesis of steroid fatty acid esters was found in brain microsomes of young male rats (55).…”

Section: Structural Identification: Some Hypothesesmentioning

confidence: 99%

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Novel lipoidal derivatives of pregnenolone and dehydroepiandrosterone and absence of their sulfated counterparts in rodent brain

Lière

Pianos

Eychenne

et al. 2004

Journal of Lipid Research

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110

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A new sample preparation method coupled to GC-MS analysis was developed and validated for quantification of sulfate esters of pregnenolone (PREG-S) and dehydroepiandrosterone (DHEA-S) in rat brain. Using a solid-phase extraction recycling protocol, the results show that little or no PREG-S and DHEA-S ( Ͻ 1 pmol/g) is present in rat and mouse brain. These data are in agreement with studies in which steroid sulfates were analyzed without deconjugation. We suggest that the discrepancies between analyses with and without deconjugation are caused by internal contamination of brain extract fractions, supposed to contain steroid sulfates, by lipoidal forms of PREG and DHEA (L-PREG and L-DHEA, respectively). These derivatives can be acylated very efficiently with heptafluorobutyric anhydride and triethylamine, and their levels in rodent brain ( ‫ف‬ 1 nmol/g) are much higher than those of their unconjugated counterparts. They are distinct from fatty acid esters, and preliminary data do not favor structures such as sulfolipids or sterol peroxides. Noncovalent interactions between steroids and proteolipidic elements, such as lipoproteins, could account for some experimental data. Given their abundance in rodent brain, the structural characterization and biological functions of L-PREG and L-DHEA in the central nervous system merit considerable attention. Four years ago, we developed and validated an analytical procedure for measuring trace amounts of neurosteroids in brain tissue by GC-MS (1). This method, which includes solid-phase extraction (SPE) and HPLC as fractionation and purification steps, is very suitable for quantifying simultaneously numerous neurosteroids in small individual regions of the central nervous system (CNS) (2) or peripheral nervous system (3) with high sensitivity and accuracy. Interest was primarily focused on pregnenolone (PREG), dehydroepiandrosterone (DHEA), and their sulfated conjugates (PREG-S and DHEA-S, respectively) and on progesterone (PROG) and allopregnanolone (3 ␣ -hydroxy-5 ␣ -pregnan-20-one).Neurosteroids are synthesized by glial cells and neurons from cholesterol or from blood-borne precursors (4). In particular, PREG-S and DHEA-S are known to be neuroactive, and their major effects are the modulation of several neuronal membrane receptors, such as ␥ -aminobutyric acid (5, 6), N -methyl-d -aspartate (7), and σ receptors, by affecting neuronal excitability and behavior (8, 9). Notably, a physiologic function of PREG-S was suggested by the positive correlation between PREG-S levels in the hippocampus of aged rats and their spatial memory performance (10). However, some studies do not favor the concept that PREG-S and DHEA-S are actually neurosteroids. Indeed, contradictory results have been obtained concerning the presence and activity of the hydroxysteroid sulfotransferase, implied in the sulfation of free steroid.

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Section: Structural Identification: Some Hypothesesmentioning

confidence: 98%

Section: Extractionmentioning

confidence: 99%

Section: Derivatization Reactionmentioning

confidence: 99%

Section: Analysis Of Preg-s and Dhea-s By Gc-ms: Improvement In Samplmentioning

confidence: 99%

Section: Structural Identification: Some Hypothesesmentioning

confidence: 99%

See 3 more Smart Citations

Novel lipoidal derivatives of pregnenolone and dehydroepiandrosterone and absence of their sulfated counterparts in rodent brain

Lière

Pianos

Eychenne

et al. 2004

Journal of Lipid Research

Self Cite

110

View full text Add to dashboard Cite

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Neuroendocrine Metabolism of Progesterone and Related Progestins

Karavolas

Hodges

2007

Ciba Foundation Symposium 153 ‐ Steroids and Neuronal Activity

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Activity and localization of 3β‐hydroxysteroid dehydrogenase/ Δ⁵‐Δ⁴‐isomerase in the zebrafish central nervous system

Sakamoto

Ukena

Tsutsui

2001

J of Comparative Neurology

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Little information is available for neurosteroidogenesis in the central nervous system (CNS) of lower vertebrates. Therefore, in the present study, we examined the enzymatic activity and localization of 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4-isomerase (3betaHSD), a key steroidogenic enzyme, in the CNS of adult male zebrafish to clarify central progesterone biosynthesis. Biochemical studies together with HPLC analysis revealed that the zebrafish brain converted pregnenolone to progesterone, suggesting the enzymatic activity of 3betaHSD. This conversion was significantly reduced by trilostane, a specific inhibitor of 3betaHSD. By using Western immunoblotting with the polyclonal antiserum directed against purified bovine adrenal 3betaHSD, a 3betaHSD-like substance was found in homogenates of the zebrafish brain. Immunocytochemical analysis was then undertaken to investigate the localization of the 3betaHSD-like substance in the zebrafish brain and spinal cord. Clusters of immunoreactive cell bodies were localized in the dorsal telencephalic areas (D), central posterior thalamic nucleus (CP), preoptic nuclei (NPO), posterior tuberal nucleus (PTN), paraventricular organ (PVO), and nucleus of medial longitudinal fascicle (NMLF). 3betaHSD-like immunoreactivity was also observed in somata of cerebellar Purkinje neurons. A widespread distribution of immunoreactive fibers was found throughout the brain and spinal cord. In addition, positively stained cells were restricted to other organs, such as the pituitary and retina. Preabsorbing the antiserum with purified bovine adrenal microsome resulted in a complete absence of 3betaHSD-like immunoreactivity. These results suggest that the fish CNS possesses steroidogenic enzyme 3betaHSD and produces progesterone. The present study further provides the first immunocytochemical mapping of the site of 3betaHSD expression in the fish CNS.

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Pregnenolone, dehydroepiandrosterone, and their sulfate and fatty acid esters in the rat brain

Cited by 113 publications

References 10 publications

Novel lipoidal derivatives of pregnenolone and dehydroepiandrosterone and absence of their sulfated counterparts in rodent brain

Novel lipoidal derivatives of pregnenolone and dehydroepiandrosterone and absence of their sulfated counterparts in rodent brain

Neuroendocrine Metabolism of Progesterone and Related Progestins

Activity and localization of 3β‐hydroxysteroid dehydrogenase/ Δ⁵‐Δ⁴‐isomerase in the zebrafish central nervous system

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Pregnenolone, dehydroepiandrosterone, and their sulfate and fatty acid esters in the rat brain

Cited by 113 publications

References 10 publications

Novel lipoidal derivatives of pregnenolone and dehydroepiandrosterone and absence of their sulfated counterparts in rodent brain

Novel lipoidal derivatives of pregnenolone and dehydroepiandrosterone and absence of their sulfated counterparts in rodent brain

Neuroendocrine Metabolism of Progesterone and Related Progestins

Activity and localization of 3β‐hydroxysteroid dehydrogenase/ Δ5‐Δ4‐isomerase in the zebrafish central nervous system

Contact Info

Product

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Activity and localization of 3β‐hydroxysteroid dehydrogenase/ Δ⁵‐Δ⁴‐isomerase in the zebrafish central nervous system