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Steroid adrenal

FIGURE 61.1 The sites of synthesis of aldosterone, cortisol, and androgens. [Pg.554]


Testiculat androgens are synthesized in the interstitial tissue by the Leydig cells. The immediate precursor of the gonadal steroids, as for the adrenal steroids, is cholesterol. The rate-limiting step, as in the adrenal, is delivery of cholesterol to the inner membrane of the mitochondria by the transport protein StAR. Once in the proper location, cholesterol is acted upon by the side chain cleavage enzyme P450scc. The conversion of cholesterol to pregnenolone is identical in adrenal, ovary, and testis. In the latter two tissues, however, the reaction is promoted by LH rather than ACTH. [Pg.442]

Adrenal steroid synthesis. The adrenal cortex consists of three histologically distinct zones the zona glomerulosa, zona fasciculata, and an innermost layer called the zona reticularis. Each zone is responsible for production of different hormones. (17 =... [Pg.686]

Funder, J. Adrenal steroids new answers, new questions Science 237 236-237,1987. [Pg.469]

Regarding the adrenal steroids, the behavioral activation of hormonal secretion in stress is part of a mechanism for restoring homeostatic balance. For example, an encounter with a predator may require rapid evasive action, in which neural activity and rapidly mobilized hormones such as epinephrine play a role. Adrenal steroid secretion is slower, reaching a peak minutes after the stressful event, and therefore is not expected to play a role in coping with the immediate situation. If the evasive action is successful and... [Pg.845]

So far, the best understood examples of genomic regulation of neuronal function stem from the actions of gonadal and adrenal steroids and thyroid hormone, and many of these actions are involved in the plasticity of behavior that results from hormonal secretion, such as changes in aggressive and reproductive behavior and... [Pg.847]

Glucocorticoid. Adrenal steroid receptors have been subdivided into two categories, one of which is the classical glucocorticoid receptor [7,19]. This receptor, cloned from human and rat sources, consists of a steroid- and DNA-binding subunit of 95 kDa [7, 19]. Such receptors, which have dissociation constants of 4-5 nM for glucocorticoids, are widely distributed across brain regions and are found in neurons and glial cells [7,19]. [Pg.852]

Low levels of adrenal steroids prevent this and stabilize the dentate granule neuron population they do this via Type I adrenal steroid receptors. [Pg.855]

The concept of allostatic load implies that there is a paradox in the actions of adrenal steroids they exert protection in the short run and have the potential to cause damage in the long run if the allostatic, that is, the adaptation-promoting, responses are not managed efficiently. [Pg.856]

FIGURE 52-10 Summary of adrenal steroid effects on neurons of the hippocampus, illustrating their ability to protect and stabilize the population of the dentate granule neurons and to potentiate damage caused by excitatory amino-acid release upon pyramidal neurons. E, estrogen. (From [41], with permission.)... [Pg.857]

McEwen, B. S., Sakai, R. R. and Spencer, R. L. Adrenal steroid effects on the brain versatile hormones with good and bad effects. In Hormonally-Induced Changes in Mind and Brain. Ed. Schulkin, J. San Diego Academic Press, 1993, ppl57-189. [Pg.857]

Retention of radiocopper injected into humans is high only 10% is excreted within 72 h in urine and feces, and 50% in four weeks (Aaseth and Norseth 1986). Most (72%) of the unabsorbed copper is excreted in the feces primarily by way of the biliary duct, the salivary glands, or the intestinal mucosa a minor portion is excreted by way of sweat and menses (Schroeder et al. 1966 USEPA 1980 ATSDR 1990). In mammals, copper is excreted mainly via the bile in association with glutathione or unidentified high-molecular-weight molecules. However, the transport mechanisms of copper from liver cells into bile are essentially unknown (Aaseth and Norseth 1986). In rats, biliary excretion of copper is increased by increased flow of bile, increased body temperature, or administration of adrenal steroids (Sugawara et al. 1994). [Pg.135]

Dhabhar, ES. et al., Differential activation of adrenal steroid receptors in neural and immune tissues of Sprague Dawley, Fischer 344, and Lewis rats, J. Neuroimmunol., 56, 77, 1995. [Pg.521]

L5. Lepore, M. J., Long-term or maintenance adrenal steroid therapy in non-tropical sprue. Am. J. Med. 25, 381-390 (1958). [Pg.117]

PXR in Adrenal Steroid Homeostasis and Drug-Hormone Interactions... [Pg.303]

Mactutus CF. 1986. Early adrenal steroid influences on neural and behavioral function. Neurotoxicology 7(2) 77-94. [Pg.270]

T. Kimura, J. J. Ting, and J. J. Huang, Studies on adrenal steroid hydroxylases. Anomalous fluorescence of a tyrosyl residue in adrenal iron-sulfur protein (adrenodoxin), J. Biol. Chem. 247, 4476-4479 (1972). [Pg.62]

Adulteration, which can be accidental or deliberate, is another problem. Many herbal products have been found to contain prescription or OTC drugs and dangerous heavy metals. In 1998, for example, the California Department of Health reported that 32% of Asian herbal medicines sold in that state contained undeclared pharmaceuticals or heavy metals. A subsequent study of more than 500 Chinese herbal medicines found that about 10% of them contained undeclared drugs or toxic levels of metals. The FDA and other investigators have also detected sildenafil, colchicine, adrenal steroids, alprazolam, and other prescription drug ingredients in products claimed to contain only natural ingredients. [Pg.527]

Drugs that can be used to control tumour cell proliferation inhibit a variety of enzymes, including thymidylate synthase and topoisomerase (Chapter 20). The enzyme aromatase converts a ring in a steroid to an aromatic ring. It converts, for example, adrenal steroid hormones into female sex hormones, which bind to oestrogenic receptors in the ovary or breast and increase the risk of ovarian or breast cancer. Aromatase inhibitors are used to treat patients with breast or ovarian cancers that are sensitive to oestrogen. Unfortunately, none of the inhibitors is specific for enzymes in tumour cells and they can therefore have severe side-effects (Chapter 21). [Pg.60]

Only if the hormone is lipid soluble, and can therefore transfer rapidly across the cell membrane, can the receptor be within the cell. Examples of such hormones include the steroid hormones (e.g. sex hormones, adrenal steroids and dihydroxycholecalciferol) and thyroxine (i.e. triiodothyronine). [Pg.257]

High-dose progestins are used as last-line endocrine therapy [223]. They inhibit the adrenal steroid biosynthesis. The decrease of estrogen levels is comparable to that caused by the administration of aromatase inhibitors. In post-menopausal women, the progestin megestrol acetate (MGA) decreases serum plasma level of DEAH, androstenedione and cortisol to less than 10% [223,224]. [Pg.70]

Oral contraceptives Adrenal steroids Cyclosporine, tacrolimus Erythropoietin... [Pg.580]

Cushing s disease (caused by a pituitary ACTH-secreting adenoma) or Cushing s syndrome from an adrenal tumour is normally treated by surgical removal of the primary lesion where possible. Cases of ectopic ACTH syndrome associated with carcinoma of the bronchus cannot be treated surgically, and often benefit from medical therapy to control adrenal steroid excess. [Pg.775]

Metyrapone is a competitive inhibitor of 11 beta hydroxylation in the adrenal cortex, and effectively inhibits cortisol production. It is used in low doses, titrated to achieve plasma cortisol levels as close as possible to normal day-time values. Occasionally it is used in higher doses combined with replacement corticosteroid treatment. Its main side effects relate to overdosage and resulting hypoadrenalism, but it can also cause hirsutism and hypertension, due to accumulation of precursor steroids. Ketoconazole is also sometimes used to suppress adrenal steroid production, but its potential for hepatotoxicity limits its... [Pg.775]

The 17- and 21-hydroxylase enzymes are associated with microsomes, whereas the ll- -hydroxylase has a mitochondrial origin. Since the last-named enzyme is not detectable in other steroid-producing tissues, the term 11-oxygenated steroids is considered synonymous with adrenal steroids. Aldosterone synthesis involves an essential 18-hydroxylation step catalyzed by P450d8 with corticosterone as the precursor this reaction also takes place within the mitochondria. [Pg.688]

Mechanism of Action A glucocorticoid that stimulates initial reaction in synthesis of adrenal steroids from cholesteroL Therapeutic Effect Increases endogenous corti-coid synthesis. [Pg.307]


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Adrenal Steroid Activity

Adrenal cortex steroid hormones

Adrenal cortical steroid hormones

Adrenal steroid research

Adrenal steroids adrenocorticotropic hormones

Adrenal steroids biosynthesis

Adrenal steroids chemical nature

Adrenal steroids cholesterol synthesis

Adrenal steroids classification

Adrenal steroids mineralocorticoids

Adrenal steroids, Urinary

Adrenal steroids, synthesis

Adrenalitis

Adrene

Adrenocortical steroids adrenal androgens

Allergy adrenal steroids

Anti-inflammatory effects adrenal steroids (=glucocorticoid

Determination of Gonadal and Adrenal Steroid Hormones

First Attempts to Localize Steroid Hormones in the Adrenal Cortex, Gonads, and Placenta

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Potency adrenal steroids

Special Concerns of Adrenal Steroid Use in Rehabilitation Patients

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Steroids, adrenal cortical

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