Topic
Pregnenolone
About: Pregnenolone is a research topic. Over the lifetime, 3539 publications have been published within this topic receiving 126444 citations. The topic is also known as: (3b)-3-hydroxy-Pregn-5-en-20-one & 3-Hydroxypregn-5-en-20-one.
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TL;DR: The results demonstrate that chemical analysis combined with the H295R cell assay is an useful tool for studying the mechanisms by which endocrine disruptors interfere with the steroidogenic pathway.
62 citations
TL;DR: Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism, whereas serum DHEa-S and PREG-S concentrations were increased but D HEA was normal in hyper thyroidism.
Abstract: Background: Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to have protective effects against cardiovascular disease, cancer, immune-modulated diseases, and aging. We examined serum concentrations of DHEA, DHEA-S, and pregnenolone sulfate (PREG-S) in patients with thyroid dysfunction.
Methods: Steroids extracted with methanol from serum sample were separated into an unconjugated fraction (DHEA) and a monosulfate fraction (DHEA-S and PREG-S), using a solid-phase extraction and an ion-exchange column. After separation of unconjugated steroids by HPLC, the DHEA concentration was measured by enzyme immunoassay. The monosulfate fraction was treated with arylsulfatase, and the freed steroids were separated by HPLC. The DHEA and PREG fractions were determined by gas chromatography–mass spectrometry, and the concentrations were converted into those of DHEA-S and PREG-S.
Results: Serum concentrations of DHEA, DHEA-S, and PREG-S were all significantly lower in patients with hypothyroidism (n = 24) than in age- and sex-matched healthy controls (n = 43). By contrast, in patients with hyperthyroidism (n = 22), serum DHEA-S and PREG-S concentrations were significantly higher, but the serum DHEA concentration was within the reference interval. Serum concentrations of these three steroids correlated with serum concentrations of thyroid hormones in these patients. Serum albumin and sex hormone-binding globulin concentrations were not related to these changes in the concentration of steroids.
Conclusions: Serum concentrations of DHEA, DHEA-S, and PREG-S were decreased in hypothyroidism, whereas serum DHEA-S and PREG-S concentrations were increased but DHEA was normal in hyperthyroidism. Thyroid hormone may stimulate the synthesis of these steroids, and DHEA sulfotransferase might be increased in hyperthyroidism.
62 citations
TL;DR: The findings show that administration of DHEA does not affect the isotopic ratio values of 16(5α)-androsten-3 α-ol and 5β-pregnane-3α,20α-diol, whereas the isotopy ratio values vary by more 5‰ upon ingestion of pregnenolone.
62 citations
TL;DR: The endometrial level of progesterone increased in the secretory phase, whereas those of estradiol and dehydroepiandrosterone decreased, and the concentration of pregnenolone in the endometrium was highly correlated with that in plasma.
61 citations
TL;DR: It is demonstrated that TGF-β1 has a second target in bovine adrenocortical cells, namely the steroidogenic acute regulatory protein (StAR), and it is likely that the TGF -β1-induced decrease of StAR expression that is reported here may be expanded to other steroidogenic cells in which a decrease of cholesterol accessibility to P450scc has been hypothesized.
61 citations