Steroid

14,000,000 Leading Edge Experts on the ideXlab platform

Scan Science and Technology

Contact Leading Edge Experts & Companies

Scan Science and Technology

Contact Leading Edge Experts & Companies

The Experts below are selected from a list of 185301 Experts worldwide ranked by ideXlab platform

William E. Rainey - One of the best experts on this subject based on the ideXlab platform.

  • adrenal androgens and androgen precursors definition synthesis regulation and physiologic actions
    Comprehensive Physiology, 2014
    Co-Authors: Adina F Turcu, Joshua M Smith, Richard J Auchus, William E. Rainey
    Abstract:

    The human adrenal produces more 19 carbon (C19) Steroids, by mass, than either glucocorticoids or mineralocorticoids. However, the mechanisms regulating adrenal C19 Steroid biosynthesis continue to represent one of the most intriguing mysteries of endocrine physiology. This review will discuss the C19 Steroids synthesized by the human adrenal and the features within the adrenal that allow production of these Steroids. Finally, we consider the effects of these Steroids in normal physiology and disorders of adrenal C19 Steroid excess. © 2014 American Physiological Society. Compr Physiol 4:1369-1381, 2014.

  • adrenal androgens and androgen precursors definition synthesis regulation and physiologic actions
    Comprehensive Physiology, 2014
    Co-Authors: Adina F Turcu, Joshua M Smith, Richard J Auchus, William E. Rainey
    Abstract:

    The human adrenal produces more 19 carbon (C19) Steroids, by mass, than either glucocorticoids or mineralocorticoids. However, the mechanisms regulating adrenal C19 Steroid biosynthesis continue to represent one of the most intriguing mysteries of endocrine physiology. This review will discuss the C19 Steroids synthesized by the human adrenal and the features within the adrenal that allow production of these Steroids. Finally, we consider the effects of these Steroids in normal physiology and disorders of adrenal C19 Steroid excess.

  • immunohistochemical and biochemical analysis of a human sertoli leydig cell tumor autonomous Steroid production characteristic of ovarian theca cells
    Journal of The Society for Gynecologic Investigation, 1995
    Co-Authors: Chiravudh Sawetawan, William E. Rainey, Ruth Ann Word, Bruce R. Carr
    Abstract:

    OBJECTIVE To ascertain the Steroidogenic profile and location of Steroidogenic enzymes in a Steroid-secreting Sertoli-Leydig cell tumor of the ovary. METHODS Steroid levels from peripheral, left ovarian (tumor), and right ovarian venous blood were measured. Tumor tissue was examined for the Steroidogenic enzymes 17 alpha-hydroxylase (P450c17) and 3 beta-hydroxySteroid dehydrogenase (3 beta HSD) by immunohistochemistry. Tumor cells were isolated and incubated in serum-free media. Thereafter, media were analyzed for Steroid production, Steroidogenic response to effectors, and metabolism of radiolabeled pregnenolone and androstenedione. RESULTS Levels of C19 Steroids and 17-hydroxyprogesterone (17OHP) were elevated in peripheral blood. The majority (80%) of Steroids in serum from the left ovarian vein (tumor) were C19 Steroids (dehydroepiandrosterone [DHEA], 45%; androstenedione, 27%, testosterone, 7%, with 13% 17OHP, 7% progesterone, and less than 1% estradiol (E2). Immunoreactivity for both P450c17 and 3 beta HSD was identified in clusters of large cells surrounded by nonimmunoreactive cells composing cord-like structures. Of the Steroids that accumulated in the incubation medium of unstimulated, freshly isolated tumor cells, 84% were C19 Steroids (DHEA, 44%; androstenedione, 36%; testosterone 2%, with 16% 17OHP and less than 1% progesterone and E2. Basal Steroid production was not stimulated by LH or FSH. However, treatment with forskolin (10 mumol/L), dibutyryl cAMP (1 mmol/L), or Steroid precursors (22-hydroxycholesterol, 1 mumol/L; pregnenolone, 1 mumol/L) increased the production of all Steroids measured. Forskolin treatment increased androstenedione (fivefold), DHEA (tenfold), and 17OHP (40-fold) compared with basal levels. Incubation of freshly isolated cells with [3H]pregnenolone demonstrated the ability of these cells to metabolize this C21 Steroid precursor to androstenedione, DHEA, and 17OHP. However, [3H]androstenedione was not readily metabolized by these cells to either estrone or testosterone. CONCLUSIONS The Steroidogenic properties of a Steroid hormone-producing tumor were described. Cells isolated from this tumor produced Steroids similar to those secreted by ovarian theca cells. These properties suggest that certain ovarian Steroidogenic tumor cells may be an appropriate model for ovarian theca cells and could be used to develop Steroid-secreting cell lines.

Guangguo Ying - One of the best experts on this subject based on the ideXlab platform.

  • how much do human and livestock actually contribute to Steroids emission and surface water pollution from past to the future a global research
    Science of The Total Environment, 2021
    Co-Authors: Qianqian Zhang, Cheng Xing, Yaya Cai, Xiaoting Yan, Guangguo Ying
    Abstract:

    Abstract A comprehensive global inventory of past, present, and future Steroid emissions was firstly developed based on the global 5′ × 5′ grids relevant data available. From 1970 to 2070, the growth rate of the annual global Steroid emission was relatively stable around 10%. At present (in 2015), the global Steroid emissions was 18,270 t, with 17% contributed by humans. Almost one-third of total animal emissions have been occurring in India and Brazil. India also had the highest value of human Steroid emissions. Regions with highest Steroid emissions were concentrated between 10° ~ 35° N and 70° ~ 90° E. The increase of sewage treatment rates can effectively reduce the total quantity of Steroids entering the environment, especially for some developing countries. But the “technology bonus” from sewage treatment process will be exhausted until to 2030. Meanwhile, global surface water pollution was predicted based on Steroid emissions into water compartment and on the digital river network with annual river discharge. The modelling results show that Steroids are widely distributed across the globe, with concentrations mostly below 100 ng/L. However, if no proper treatment measures for animal excretions, in another 100 years, the range of the surface water contaminated by Steroids will increase by 1.2 times. The Nile River resulted as the most polluted among the eight world's longest and famous rivers during the whole period investigated. Various measured concentrations worldwide validated our modelling result. The global Steroid emission inventory and surface water pollution from past to the future will stand as an important data and knowledge base for the management of pollution from different types of Steroids at global and regional level.

  • persistence of androgens progestogens and glucocorticoids during commercial animal manure composting process
    Science of The Total Environment, 2019
    Co-Authors: Qianqian Zhang, Jinna Zhang, Lei Yang, Min Zhang, Yousheng Liu, Jianliang Zhao, Guangguo Ying
    Abstract:

    Abstract Animal manure contains various organic contaminants such as Steroids. The fate of these Steroids during composting is still unknown. Here we investigated the fate of androgens, progestogens, and glucocorticoids during animal manure composting and evaluated their residues in compost-applied soils. The results showed the presence of 16 Steroid hormones in the initial compost with concentrations ranging from 3.26 ng/g dw (Cortisol) to 2520 ng/g dw (5α-dihydroprogesterone). The concentrations of almost all detected hormones increased on the 2nd day of composting, and some of them increased several or even dozens of times. Steroids such as hydroxyprogesterone caproate, melengestrol acetate, and methyltestosterone were not found in the initial compost but later detected during the composting process. After 171 days of composting, only 40.4% of detected Steroid hormones was removed, and the total concentration of detected Steroids was still as high as 3210 ng/g dw. The removal rates of some target compounds were negative, especially for the natural androgens androsta-1,4-diene-3,17-dione and the synthetic androgen 17β-boldenone whose concentrations significantly increased by the end of composting, indicating conversion from their conjugates or transformation from other Steroids. The Steroid hormones were mainly eliminated in the first three weeks; prolonged composting time did not obviously promote further removal. The variations in Steroid concentration were related to the changes in compost properties such as pH and temperature during the composting process. The dissipation of Steroid hormones was also linked to the changes of microbial communities in the compost to some extent. Twelve Steroids were detected in the compost-treated soils of a kailyard, while 26 Steroid hormones were detected in the roots of Chinese cabbages grown on the soil. The results suggest that the application of manure compost product can lead to soil contamination and plant uptake.

Adina F Turcu - One of the best experts on this subject based on the ideXlab platform.

  • adrenal androgens and androgen precursors definition synthesis regulation and physiologic actions
    Comprehensive Physiology, 2014
    Co-Authors: Adina F Turcu, Joshua M Smith, Richard J Auchus, William E. Rainey
    Abstract:

    The human adrenal produces more 19 carbon (C19) Steroids, by mass, than either glucocorticoids or mineralocorticoids. However, the mechanisms regulating adrenal C19 Steroid biosynthesis continue to represent one of the most intriguing mysteries of endocrine physiology. This review will discuss the C19 Steroids synthesized by the human adrenal and the features within the adrenal that allow production of these Steroids. Finally, we consider the effects of these Steroids in normal physiology and disorders of adrenal C19 Steroid excess.

  • adrenal androgens and androgen precursors definition synthesis regulation and physiologic actions
    Comprehensive Physiology, 2014
    Co-Authors: Adina F Turcu, Joshua M Smith, Richard J Auchus, William E. Rainey
    Abstract:

    The human adrenal produces more 19 carbon (C19) Steroids, by mass, than either glucocorticoids or mineralocorticoids. However, the mechanisms regulating adrenal C19 Steroid biosynthesis continue to represent one of the most intriguing mysteries of endocrine physiology. This review will discuss the C19 Steroids synthesized by the human adrenal and the features within the adrenal that allow production of these Steroids. Finally, we consider the effects of these Steroids in normal physiology and disorders of adrenal C19 Steroid excess. © 2014 American Physiological Society. Compr Physiol 4:1369-1381, 2014.

Jinna Zhang - One of the best experts on this subject based on the ideXlab platform.

  • persistence of androgens progestogens and glucocorticoids during commercial animal manure composting process
    Science of The Total Environment, 2019
    Co-Authors: Qianqian Zhang, Jinna Zhang, Lei Yang, Min Zhang, Yousheng Liu, Jianliang Zhao, Guangguo Ying
    Abstract:

    Abstract Animal manure contains various organic contaminants such as Steroids. The fate of these Steroids during composting is still unknown. Here we investigated the fate of androgens, progestogens, and glucocorticoids during animal manure composting and evaluated their residues in compost-applied soils. The results showed the presence of 16 Steroid hormones in the initial compost with concentrations ranging from 3.26 ng/g dw (Cortisol) to 2520 ng/g dw (5α-dihydroprogesterone). The concentrations of almost all detected hormones increased on the 2nd day of composting, and some of them increased several or even dozens of times. Steroids such as hydroxyprogesterone caproate, melengestrol acetate, and methyltestosterone were not found in the initial compost but later detected during the composting process. After 171 days of composting, only 40.4% of detected Steroid hormones was removed, and the total concentration of detected Steroids was still as high as 3210 ng/g dw. The removal rates of some target compounds were negative, especially for the natural androgens androsta-1,4-diene-3,17-dione and the synthetic androgen 17β-boldenone whose concentrations significantly increased by the end of composting, indicating conversion from their conjugates or transformation from other Steroids. The Steroid hormones were mainly eliminated in the first three weeks; prolonged composting time did not obviously promote further removal. The variations in Steroid concentration were related to the changes in compost properties such as pH and temperature during the composting process. The dissipation of Steroid hormones was also linked to the changes of microbial communities in the compost to some extent. Twelve Steroids were detected in the compost-treated soils of a kailyard, while 26 Steroid hormones were detected in the roots of Chinese cabbages grown on the soil. The results suggest that the application of manure compost product can lead to soil contamination and plant uptake.

Gustav Akk - One of the best experts on this subject based on the ideXlab platform.

  • occupation of either site for the neuroSteroid allopregnanolone potentiates the opening of the gabaa receptor induced from either transmitter binding site
    Molecular Pharmacology, 2011
    Co-Authors: John Bracamontes, Joe Henry Steinbach, Megan Mccollum, Caroline Esch, Jason Ann, Gustav Akk
    Abstract:

    Potentiating neuroactive Steroids are potent and efficacious modulators of the GABAA receptor that act by allosterically enhancing channel activation elicited by GABA. Steroids interact with the membrane-spanning domains of the α subunits of the receptor, whereas GABA binds to pockets in the interfaces between β and α subunits. Steroid interaction with a single site is known to be sufficient to produce potentiation, but it is not clear whether effects within the same β-α pair mediate potentiation. Here, we have investigated whether the sites for GABA and Steroids are functionally linked (i.e., whether the occupancy of a Steroid site selectively affects activation elicited by GABA binding to the transmitter binding site within the same β-α pair). For that, we used receptors formed of mutated concatenated subunits to selectively eliminate one of the two GABA sites and one of the two Steroid sites. The data demonstrate that receptors containing a single functional GABA site are potentiated by the neuroSteroid allopregnanolone regardless of whether the Steroid interacts with the α subunit from the same or the other β-α pair. We conclude that Steroids potentiate the opening of the GABAA receptor induced by either agonist binding site.

  • Mechanisms of neuroSteroid interactions with GABAA receptors
    Pharmacology & therapeutics, 2007
    Co-Authors: Gustav Akk, Joe Henry Steinbach, Charles F. Zorumski, Douglas F. Covey, Alex S. Evers, Steven Mennerick
    Abstract:

    Neuroactive Steroids have some of their most potent actions by augmenting the function of GABAA receptors. Endogenous Steroid actions on GABAA receptors may underlie important effects on mood and behavior. Exogenous neuroactive Steroids have potential as anesthetics, anticonvulsants, and neuroprotectants. We have taken multiple approaches to understand more completely the interaction of neuroactive Steroids with GABAA receptors. We have developed many novel Steroid analogues in this effort. Recent work has resulted in synthesis of new enantiomer analogue pairs, novel ligands that probe various properties of the Steroid pharmacophore, fluorescent neuroactive Steroid analogues, and photoaffinity labels. Using these tools, combined with receptor binding and electrophysiological assays, we have begun to untangle the complexity of Steroid actions at this important class of ligand-gated ion channel.

  • NeuroSteroid Access to the GABAA Receptor
    The Journal of neuroscience : the official journal of the Society for Neuroscience, 2005
    Co-Authors: Gustav Akk, Hong-jin Shu, Cunde Wang, Joe Henry Steinbach, Charles F. Zorumski, Douglas F. Covey, Steven Mennerick
    Abstract:

    GABAA receptors are a pivotal inhibitory influence in the nervous system, and modulators of the GABAA receptor are important anesthetics, sedatives, anticonvulsants, and anxiolytics. Current views of receptor modulation suggest that many exogenous drugs access and bind to an extracellular receptor domain. Using novel synthetic Steroid analogs, we examined the access route for neuroactive Steroids, potent GABAA receptor modulators also produced endogenously. Tight-seal recordings, in which direct aqueous drug access to receptor was prevented, demonstrated that Steroids can reach the receptor either through plasma membrane lateral diffusion or through intracellular routes. A fluorescent neuroactive Steroid accumulated intracellularly, but recordings from excised patches indicated that the intracellular reservoir is not necessary for receptor modulation, although it can apparently equilibrate with the plasma membrane within seconds. A membrane impermeant neuroactive Steroid modulated receptor activity only when applied to the inner membrane leaflet, demonstrating that the Steroid does not access an extracellular modulatory site. Thus, neuroactive Steroids do not require direct aqueous access to the receptor, and membrane accumulation is required for receptor modulation.