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Vitamins and Hormones

Gerald Litwack
No abstract text is available yet for this article.
2018: Vitamins and Hormones
Maria Sonia Baquedano, Gabriela Guercio, Mariana Costanzo, Roxana Marino, Marco A Rivarola, Alicia Belgorosky
3βHSD2 enzyme is crucial for adrenal and gonad steroid biosynthesis. In enzyme deficiency states, due to recessive loss-of-function HSD3B2 mutations, steroid flux is altered and clinical manifestations result. Deficiency of 3βHSD2 activity in the adrenals precludes normal aldosterone and cortisol synthesis and the alternative backdoor and 11-oxygenated C19 steroid pathways and the flooding of cortisol precursors along the Δ5 pathway with a marked rise in DHEA and DHEAS production. In gonads, it precludes normal T and estrogen synthesis...
2018: Vitamins and Hormones
Sónia do Vale, Carles Escera
Steroid hormones are important regulators of brain development, physiological function, and behavior. Among them, dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulfate (DHEAS) also do modulate emotional processing and may have mood enhancement effects. This chapter reviews the studies that bear relation to DHEA and DHEAS [DHEA(S)] and brain emotional processing and behavior. A brief introduction to the mechanisms of action and variations of DHEA(S) levels throughout life has also been forward in this chapter...
2018: Vitamins and Hormones
Gal Yadid, Hadas Ahdoot-Levi, Tzofnat Bareli, Rachel Maayan, Abraham Weizman
Drug addiction has a great negative influence on society, both social and economic burden. It was widely thought that addicts could choose to stop using drugs if only they had some self-control and principles. Nowadays, science has changed this view, defining drug addiction as a complex brain disease that affects behavior in many ways, both biological and psychological. Currently there is no ground-breaking reliable treatment for drug addiction. For more than a decade we are researching an alternative approach for intervention with drug craving and relapse to its usage, using DHEA, a well-being and antiaging food supplement...
2018: Vitamins and Hormones
Kai Huang, Li-Dong Wu, Jia-Peng Bao
Despite an increased understanding of the pathogenesis of osteoarthritis (OA) and the availability of a number of drugs designed to ameliorate its symptoms, a successful disease-modifying therapy remains elusive. Recent lines of evidence suggest that dehydroepiandrosterone (DHEA), a 19-carbon steroid hormone classified as an adrenal androgen, exerts a chondroprotective effect in OA patients, and it has been proven to be an effective DMOAD candidate that slows OA progression. However, the exact mechanisms underlying its anti-OA effect is largely unknown...
2018: Vitamins and Hormones
Kazutaka Aoki, Yasuo Terauchi
Type 2 diabetes is a metabolic disorder that is characterized by an impaired capacity to secrete insulin, insulin resistance, or both. Dehydroepiandrosterone (DHEA), a steroid hormone produced by the adrenal cortex, has been reported to have beneficial effects on diabetes mellitus and obesity in animal models. DHEA and DHEA-sulfate (DHEA-S) have been reported to increase not only insulin secretion of the pancreas but also insulin sensitivity of the liver, adipose tissue, and muscle. We investigated the effects of DHEA on glucose metabolism in animal models and reported decrease of liver gluconeogenesis...
2018: Vitamins and Hormones
P Mannella, T Simoncini, M Caretto, A R Genazzani
The dehydroepiandrosterone and its metabolite, dehydroepiandrosterone sulfate, have been for a long while at the center of interest for endocrinologists and cardiologists. Consolidated data show that the dehydroepiandrosterone and the dehydroepiandrosterone sulfate present protective actions on the cardiovascular system. These actions are accomplished directly through target tissues such as endothelial cells, smooth muscle cells, and cardiomyocytes. At this level, they are able to activate a complex group of receptor, not completely identified, which modulate important functions such as vasodilation, antiinflammation, and antithrombosis...
2018: Vitamins and Hormones
Trevor M Penning
Dehydroepiandrosterone (DHEA)-SO4 of adrenal origin is the major C19 steroid in the serum. It is a precursor of intratumoral androgen biosynthesis in patients with advanced prostate cancer following chemical or surgical castration. DHEA is a product of the P450c17 (17α-hydroxylase-17,20-lyase) enzyme. Despite inhibition of P450c17 with new agents, e.g., Abiraterone acetate, Orterenol, and Galeterone, the level of enzyme inhibition rarely exceeds 90% leaving behind a significant depot for androgen biosynthesis within the tumor...
2018: Vitamins and Hormones
Barbara J Clark, Russell A Prough, Carolyn M Klinge
Dehydroepiandrosterone (3β-hydroxy-5-androsten-17-one, DHEA) and its sulfated metabolite DHEA-S are the most abundant steroids in circulation and decline with age. Rodent studies have shown that DHEA has a wide variety of effects on liver, kidney, adipose, reproductive tissues, and central nervous system/neuronal function. The mechanisms by which DHEA and DHEA-S impart their physiological effects may be direct actions on plasma membrane receptors, including a DHEA-specific, G-protein-coupled receptor in endothelial cells; various neuroreceptors, e...
2018: Vitamins and Hormones
Rolando Vegliante, Maria R Ciriolo
Dehydroepiandrosterone (DHEA) is the most abundant steroid hormone in human serum and a precursor of sexual hormones. Its levels, which are maximum between the age of 20 and 30, dramatically decline with aging thus raising the question that many pathological conditions typical of the elderly might be associated with the decrement of circulating DHEA. Moreover, since its very early discovery, DHEA and its metabolites have been shown to be active in many pathophysiological contexts, including cardiovascular disease, brain disorders, and cancer...
2018: Vitamins and Hormones
Shuanhu Zhou, Julie Glowacki
In humans, dehydroepiandrosterone (DHEA), secreted mainly from the adrenal cortex, and its sulfate ester, DHEAS, are the most abundant circulating steroids. DHEA/DHEAS possess pleiotropic effects in human aging, bone, metabolic diseases, neurologic function/neurodegenerative diseases, cancer, immune system and disorders, cardiovascular diseases, diabetes, muscle function, sexual dysfunction, and other health conditions. The age-related reduced levels of DHEA and DHEAS are associated with bone mineral density measures of osteopenia and osteoporosis...
2018: Vitamins and Hormones
Bindu N Chimote, Natchandra M Chimote
Steroid hormones form an integral part of normal development in mammalian organisms. Cholesterol is the parent compound from which all steroid hormones are synthesized. The product pregnenolone formed from cholesterol serves as precursor for mineralocorticoids, glucocorticoids, as well as dehydroepiandrosterone (DHEA) and its derived sexual hormones. DHEA assumes the prohormone status of a predominant endogenous precursor and a metabolic intermediate in ovarian follicular steroidogenesis. DHEA supplementation has been used to enhance ovarian reserve...
2018: Vitamins and Hormones
Koji Sato, Motoyuki Iemitsu
Dehydroepiandrosterone (DHEA) is a precursor of sex steroid hormones and is converted to testosterone and estradiol. Normally, androgens and estrogens produced adrenal cortex, testis, and ovary; however, recent studies revealed androgens and estrogens are synthesized by peripheral tissues such as brain, skin, liver, kidney, bone, etc. We found skeletal muscles are also capable of synthesizing androgens and estrogens from DHEA. Circulating DHEA provides substrates required for conversion into potent androgens and estrogens in peripheral tissues...
2018: Vitamins and Hormones
Bruno D Arbo, Felipe S Ribeiro, Maria F Ribeiro
Dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) are the most abundant steroid hormones in the systemic circulation of humans. Due to their abundance and reduced production during aging, these hormones have been suggested to play a role in many aspects of health and have been used as drugs for a multiple range of therapeutic actions, including hormonal replacement and the improvement of aging-related diseases. In addition, several studies have shown that DHEA and DHEAS are neuroprotective under different experimental conditions, including models of ischemia, traumatic brain injury, spinal cord injury, glutamate excitotoxicity, and neurodegenerative diseases...
2018: Vitamins and Hormones
Tracey Quinn, Ronda Greaves, Emilio Badoer, David Walker
Dehydroepiandrosterone (DHEA) and its sulfated congener (DHEAS) are the principal C19 steroid produced by the adrenal gland in many mammals, including humans. It is secreted in high concentrations during fetal life, but synthesis decreases after birth until, in humans and some other primates, there is a prepubertal surge of DHEA production by the adrenal gland-a phenomenon known as adrenarche. There remains considerable uncertainty about the physiological role of DHEA and DHEAS. Moreover, the origin of the trophic drives that determine the waxing and waning of DHEA synthesis are poorly understood...
2018: Vitamins and Hormones
Sean P Prall, Michael P Muehlenbein
DHEA and DHEA-S have numerous associations with multiple aspects of immune function and are often characterized as beneficial and supportive of immunocompetence. However, closer inspection of these studies reveals confusion regarding the immunological components modified, the mechanisms of action, and degree of impact, and even whether these hormones even have direct action or are mediated by metabolites and interactions with other hormones and hormone receptors. Additionally, much of the research is conducted on rodent models using very high concentrations of hormone supplements, which may not be representative of the effects of these hormones in natural circulating concentrations, or may not translate to human physiology in a meaningful way...
2018: Vitamins and Hormones
Carolyn M Klinge, Barbara J Clark, Russell A Prough
The discovery of "oestrus-producing" hormones was a major research breakthrough in biochemistry and pharmacology during the early part of the 20th century. The elucidation of the molecular weight and chemical structure of major oxidative metabolites of dehydroepiandrosterone (DHEA) led to the award of the Nobel Prize in 1939 to Adolf Frederick Johann Butenandt and Leopold Ruzicka. Considered a bulk androgen in the circulation, DHEA and its sulfated metabolite DHEA-S can be taken up by most tissues where the sterols are metabolized to active androgenic and estrogenic compounds needed for growth and development...
2018: Vitamins and Hormones
Gerald Litwack
No abstract text is available yet for this article.
2018: Vitamins and Hormones
Peyton W Weems, Michael N Lehman, Lique M Coolen, Robert L Goodman
Work over the last 15 years on the control of pulsatile LH secretion has focused largely on a set of neurons in the arcuate nucleus (ARC) that contains two stimulatory neuropeptides, critical for fertility in humans (kisspeptin and neurokinin B (NKB)) and the inhibitory endogenous opioid peptide (EOP), dynorphin, and are now known as KNDy (kisspeptin-NKB-dynorphin) neurons. In this review, we consider the role of each of the KNDy peptides in the generation of GnRH pulses and the negative feedback actions of ovarian steroids, with an emphasis on NKB and dynorphin...
2018: Vitamins and Hormones
K M J Menon, Bindu Menon, Thippeswamy Gulappa
The expression of luteinizing hormone receptor (LHR) in the mammalian ovary is regulated in response to changes in the secretion of follicle-stimulating hormone and luteinizing hormone by the anterior pituitary, at least in part, through posttranscriptional mechanisms. The steady-state levels of LHR mRNA are maintained by controlling its rate of degradation by an RNA-binding protein designated as LHR mRNA-binding protein (LRBP). LRBP forms a complex with LHR mRNA and targets it for degradation in the p bodies...
2018: Vitamins and Hormones
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