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Steroid biosynthesis
About: Steroid biosynthesis is a research topic. Over the lifetime, 1721 publications have been published within this topic receiving 58977 citations.
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TL;DR: Results suggest that NP exhibited clearly estrogenic activity on the three chemicals in oocyte steroid biosynthesis, as compared to BPA treatment, which increased the androgen, while estrogen synthesis was slightly inhibited.
Abstract: In this study, fully vitellogenic oocytes of the longchin goby (Chasmichthys dolichognathus) were exposed to in vitro xenoestrogens such as diethylstilbestrol (DES), bisphenol A (BPA) and nonylphenol (NP) at concentrations of 100 ng/ml in the presence of [3H]17α-hydroxyprogesterone as precursor. The major metabolites produced in vitro are progestogens [17α-hydroxy,20α-dihydroprogesterone (17α20αOHP) and 17α-hydroxy,20β-dihydroprogesterone (17α20βOHP)], androgens [androstenedione (A4) and testosterone (T)] and estrogens [estrone (E1) and estradiol-17β (E2)]. Comparative activities of these chemicals in oocyte steroid biosynthesis showed as follows: NP treatment resulted in clear stimulation of estrogen production, while the opposite occurred in DES treated incubation. Treatment with DES resulted in a higher synthesis of 17α20αOHP. BPA treatment increased the androgen, while estrogen synthesis was slightly inhibited. These results suggest that NP exhibited clearly estrogenic activity on the three chemicals.
16 citations
TL;DR: Results indicate that PTP activity participates in StAR protein induction and led us to attribute to the PKA-mediated PTP activation in steroidogenic systems a functional role, as mediator of Star protein induction.
Abstract: A key regulatory step in the steroidogenic hormones signaling pathway is the synthesis of steroidogenic acute regulatory protein (StAR). This protein facilitates the delivery of cholesterol to the inner mitochondrial membrane, the rate-limiting step in steroidogenesis. ACTH and LH pathway also includes tyrosine dephosphorylation processes. Indeed, our previous studies have demonstrated that both hormones increase protein tyrosine phosphatase (PTP) activity by a PKA-dependent mechanism and that the action of PTPs is required for the stimulation of steroid biosynthesis in adrenal and Leydig cells. In order to test the putative relationship between PTP activity and StAR protein induction in adrenocortical cells, in the present study we evaluated steroid production and StAR protein level in Y1 adrenocortical cells under PTP inhibition. Phenylarsine oxide (PAO), a powerful cell permeable PTP inhibitor, reduced ACTH-stimulated steroidogenesis in a concentration-dependent fashion. A concentration of 2.5 µM of th...
16 citations
TL;DR: Findings indicate that the steroidogenic effeciency of CAMP cannot be explained by an accumulation of steroid precursors beyond this important step in steroid biosynthesis.
Abstract: When added simultaneously with CAMP (adenosine-3′,5′-monophosphate), inhibitors of protein synthesis block the steroidogenic effect of CAMP in rat adrenal sections in vitro. However, after prior stimulation of adrenal sections by CAMP for 10–30 min, heightened rates of steroidogenesis persist despite removing CAMP from the medium and/or adding cycloheximide or chloramphenicol. This previously established steroidogenic effect continues undiminished for 30–40 min, and then decays with a half-life of about 25 min. Virtually identical results are obtained when ACTH is employed as the stimulator, and this is compatible with the hypothesis that CAMP is the intracellular mediator of ACTH action. Since aminoglutethimide, an inhibitor of cholesterol side chain cleavage, largely blocks the persistent steroidogenic effect of CAMP, the latter effect cannot be explained by an accumulation of steroid precursors beyond this important step in steroid biosynthesis. Thepresent findings indicate that the steroidogenic effec...
16 citations
TL;DR: RNA-sequencing runs were performed on the hepatic libraries of adult male rare minnow after TBT exposure and the results offered new mechanisms underlying the toxicology of TBT and represented a starting point for detailed mechanistic links should be explored.
16 citations
TL;DR: It is suggested that mitochondrial metabolism of 17P(4) may constitute a new sensitive probe for the assessment of endocrine disruption in fish.
16 citations