Nano-electrospray tandem mass spectrometry for the analysis of neurosteroid sulphates†

Griffiths, William J.; Liu, Suya; Yang, Yang; Purdy, Robert H.; Sjövall, Jan

doi:10.1002/(sici)1097-0231(19990815)13:15<1595::aid-rcm681>3.0.co;2-1

Cited by 50 publications

(51 citation statements)

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“…Allopregnanolone and related neurosteroids have been commonly analyzed by sensitive radioimmunoassay, gas chromatography, and mass spectrometry assays (Purdy et al, 1990;Bicikova et al, 1995;Griffiths et al, 1999;Chatman et al, 1999;Kim et al, 2000). Many studies describe derivatization for the trace analysis of neurosteroids by mass spectrometry (Cheney et al, 1995;Lierre et al, 2000;Higashi et al, 2005).…”

Section: Analysis Of Neurosteroidsmentioning

confidence: 99%

“…Moreover, liquid phase extraction followed by mass spectrometry with a short run time is the most specific and accurate method for the analysis of 3α-hydroxy neurosteroids in human and rat plasma (Cheney et al, 1995;Ramu et al, 2001). Steroids have been commonly analyzed using liquidliquid extraction and either ECNCI-LC/MS/MS or APCI-LC/MS/MS modes (Griffiths et al, 1999;Kim et al, 2000;Kobayashi et al, 1993;Fredline et al, 1997;Vallee et al, 2000). Influence of eluent composition on ionization efficiency has been extensively studied (Volmer and Hui, 1997).…”

Section: Analysis Of Neurosteroidsmentioning

confidence: 99%

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Mass spectrometric assay and physiological–pharmacological activity of androgenic neurosteroids

Reddy¹

2008

Neurochemistry International

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Steroid hormones play a key role in the pathophysiology of several brain disorders. Testosterone modulates neuronal excitability, but the underlying mechanisms are obscure. There is emerging evidence that testosterone-derived "androgenic neurosteroids", 3α-androstanediol and 17β-estradiol, mediate the testosterone effects on neural excitability and seizure susceptibility. Testosterone undergoes metabolism to neurosteroids via two distinct pathways. Aromatization of the A-ring converts testosterone into 17β-estradiol. Reduction of testosterone by 5α-reductase generates 5α-dihydrotestosterone, which is then converted to 3α-androstanediol, a powerful GABA A receptormodulating neurosteroid with anticonvulsant properties. Although the 3α-androstanediol is an emerging neurosteroid in the brain, there is no specific and sensitive assay for determination of 3α-androstanediol in biological samples. This article describes the development and validation of mass spectrometric assay of 3α-androstanediol, and the molecular mechanisms underlying the testosterone modulation of seizure susceptibility. A liquid chromatography-tandem mass spectrometry assay to measure 3α-androstanediol is validated with excellent linearity, specificity, sensitivity, and reproducibility. Testosterone modulation of seizure susceptibility is demonstrated to occur through its conversion to neurosteroids with "anticonvulsant" and "proconvulsant" actions and hence the net effect of testosterone on neural excitability and seizure activity depends on the levels of distinct testosterone metabolites. The proconvulsant effect of testosterone is associated with increases in plasma 17β-estradiol concentrations. The 5α-reduced metabolites of testosterone, 5α-dihydrotestosterone and 3α-androstanediol, had powerful anticonvulsant activity. Overall, the testosterone-derived neurosteroids 3α-androstanediol and 17β-estradiol could contribute to the net cellular actions of testosterone in the brain. Because 3α-androstanediol is a potent positive allosteric modulator of GABA A receptors, it could serve as an endogenous neuromodulator of neuronal excitability in men. The 3α-androstanediol assay is an important tool in this area because of the growing interest in the potential to use adjuvant aromatase inhibitor therapy to improve treatment of epilepsy.

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Section: Analysis Of Neurosteroidsmentioning

confidence: 99%

Section: Analysis Of Neurosteroidsmentioning

confidence: 99%

Mass spectrometric assay and physiological–pharmacological activity of androgenic neurosteroids

Reddy¹

2008

Neurochemistry International

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“…For this reason, the sulfated steroids must be hydrolyzed and derivatized before their analysis by GC-MS. Some groups have evaluated the potential of direct detection methods such as high performance liquid chromatography-electrospray ionizationtandem mass spectrometry (HPLC-ESI-MS/MS) (35) and capillary column HPLC-nanoelectrospray ionization-MS/ MS (27,33,36) for quantification of sulfated steroids in rat brain. Furthermore, ELISAs were developed to measure DHEA-S (24) and PREG-S (25, 26) levels in rat brain by using anti-DHEA-S and anti-PREG-S antibodies, respectively.…”

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

confidence: 99%

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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“…Among lipids, especially for negatively charged steroid precursor ions (sulfated, sulfonated or glucuronidated molecules) a product ion nomenclature was reported by Griffiths et al [14][15][16] involving typically two-bond ring cleavages. This nomenclature was later also developed and utilized for positive precursor ions of Girad P-derivatized steroids [17][18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

A universal product ion nomenclature for [M−H]−, [M+H]+ and [M+nNa−(n−1)H]+ (n=1–3) glycerophospholipid precursor ions based on high-energy CID by MALDI-TOF/RTOF mass spectrometry

Pittenauer

Allmaier

2011

International Journal of Mass Spectrometry

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Nano-electrospray tandem mass spectrometry for the analysis of neurosteroid sulphates†

Cited by 50 publications

References 47 publications

Mass spectrometric assay and physiological–pharmacological activity of androgenic neurosteroids

Mass spectrometric assay and physiological–pharmacological activity of androgenic neurosteroids

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

A universal product ion nomenclature for [M−H]−, [M+H]+ and [M+nNa−(n−1)H]+ (n=1–3) glycerophospholipid precursor ions based on high-energy CID by MALDI-TOF/RTOF mass spectrometry

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