Adrenal steroids adrenocorticotropic hormones

Amri H, Drieu K, Papadopoulos V. (1997). Ex vivo regulation of adrenal cortical cell steroid and protein synthesis, in response to adrenocorticotropic hormone stimulation, by the Ginkgo biloba extract EGb 761 and isolated ginkgolide B. Endocrinology. 138(12) 5415-26. 

Adrenocorticotropic hormone (ACTH] t adrenal steroid synthesis (e.g., cortisol]... 

The adrenal glands are located anatomically above the kidneys. They comprise a three-layer cortex and a medulla. The medulla is the source of catecholamines such as epinephrine, the fight-or-flight hormone. The cortex is the source of aldosterone, the primary mineralocorticoid that is involved in the regulation of sodium reabsorption in the kidneys. In addition, the cortex is also the source of steroids known as glucocorticoids, of which cortisol is the principal endogenous representative. Synthesis and release of cortisol is under the control of adrenocorticotropic hormone (ACTH). 

Adrenocorticotropic hormone (Fig. 4) stimulates the cells of the adrenal cortex into the secretion and production of steroid hormones. Conversely, the pituitary secretion of ACTH is inhibited by the adrenal hormones via a feedback mechanism. 

Adrenocorticotropic hormone (ACTH) Polypeptide with 39 amino acids Corticotropin-releasing hormone (CRH) peptide with 41 amino acids Unknown Causes release of steroid hormones from adrenal cortex... 

Van der Vies (1957) Experience with an assay of adrenocorticotropic hormone based on the steroid output of rat adrenals in vitro. Acta Physiol Pharmacol Neerl 5 361-384 Vogel (1969) Tierexperimentelle Untersuchungen iiber syn-thetische Peptide mit Corticotropinaktivitat. A Vergleich mit dem III. Internationalen Standard fur Corticotropin. Arzneim Forsch/Drug Res 19 20-24... 

Intralesional injection of steroid can lead to adrenal suppression. Infents and small children are especially susceptible, because a given amoimt of steroid is distributed in a smaller volume of fluid and tissue compartments. Infents injected with mixtiu es of triamcinolone acetonide and betamethasone or dexamethasone fiar periocular hemangiomas exhibited depressed serum cortisol and adrenocorticotropic hormone levels. The adrenal suppression can last up to 5 months and can result in weight loss and growth retardation. It is not known whether other corticosteroid preparations would produce similar effects or which other fectors might influence these results. In general, topical and periocular use of steroids produces minimal systemic effects. Withdrawal of topical or periocular steroids does not generally cause adrenal crisis. 

The use of corticosteroids in the treatment of septic shock has been a topic of controversy for many years. A meta-analysis of early studies of steroids in sepsis demonstrated a lack of benefit and potential harm in sepsis and septic shock. There is a renewed interest in corticosteroid use because of the increased awareness of adrenocortical insufficiency in critically ill patients with septic shock. Relative adrenal insufficiency has been defined as a poor adrenal response [<250 nmol/L (9 mcg/dL) irrespective of the initial serum cortisol level] to a dose of synthetic adrenocorticotropic hormone (ACTH), indicating a low fnnctional reserve of the adrenal cortex. Although absolute insufficiency is rare, relative adrenocortical insufficiency in the presence of normal or high cortisol concentrations at baseline is present in 30% to 50% of patients with septic shock and is associated with a poor outcome. ... 

Sachazkaja, T., Influence of adrenocorticotropic hormone on the biosynthesis of A -3-unsaturated steroids in the adrenals of human foetuses. Excerpta Med. Intern. Congr. Ser. Ill, 287-288 (1966). 

Corticotropin (ACTH) (adrenocorticotropic hormone) Stimulates steroid synthesis in adrenal cortex... 

The adrenal glands, which are divided into the medulla (core) and the cortex (outer layer), furnish catecholamines and steroids, respectively. The catecholamines are hormonally active, and consist of norepinephrine and epinephrine. Steroids variously affect carbohydrate, protein, and lipid metabolism, regulate the sall/water losses of the kidneys, and affect sexual development and function. Androgens and estrogens fall in the last-mentioned category. Another adrenal hormone of note is ACTH, or adrenocorticotropic hormone. Cortisol is an adrenal product, which can be converted to cortisone. 

Deficiency of 21-hydroxylase inhibits the synthesis of glucocorticoids (e.g., cortisol) and mineralocorticoids (e.g., aldosterone), leading to overproduction of testosterone in the adrenal glands and underproduction of cortisol. The latter effectively increases adrenocorticotropic hormone (ACTH), which stimulates the adrenals to grow and synthesize steroids, exacerbating the testosterone overproduction. This leads to masculinization of females. 

ENDOCRINE SYSTEM A number of endocrine tissues respond to PGs. In a number of species, the systemic administration of PGE increases circulating concentrations of adrenocorticotropic hormone (ACTH), growth hormone, prolactin, and gonadotropins. Other effects include stimulation of steroid production by the adrenals, stimulation of insulin release, and thyrotropinlike effects on the thyroid. The critical role of PGF in parturition relies on its ability to induce an oxytocin-dependent decline in progesterone levels. PGE works as part of a positive-feedback loop to induce oocyte maturation required for fertihzation during and after ovulation. 

The final step in cortisol synthesis requires transport of 11-deoxycortisol back to the inner membrane of the mitochondria, where P450cn (11-P-hydroxylase) receives electrons from electron transport protein intermediates (adrenodoxin, which when oxidized is reduced by adrenodoxin reductase). The enzyme then transfers these reducing equivalents by way of oxygen to 11-deoxycortisol for hydroxylation at Cl 1 to form cortisol. The rate of biosynthesis of cortisol and other adrenal steroids is dependent on stimulation of the adrenal cortical cells by adrenocorticotropic hormone (ACTH). 

Adrenocorticotropic hormone 39 Stimulates production of adrenal cortex steroids (cortisol and costicosterone). 

Another important peptide hormone is adrenocorticotropic hormone (ACTH). It is synthesized by the pituitary gland and consists of a single polypeptide chain of 39 amino acid residues with no disulfide bridges (see I Figure 9.3). The major function of ACTH is to regulate the production of steroid hormones in the cortex of the adrenal gland. > Table 9.2 lists these and some other important peptide or protein hormones. 

Adrenal corticosteroids, adrenocorticoids, corticosteroids, corticoids, cortins an important group of steroid hormones, formed in the adrenal cortex in response to adrenocorticotropic hormone [ACTH, Corticotropin (see)]. A.c. are structurally related to pregnane (see Steroids) they contain a carboxyl group with a neighboring a,p-unsaturated bond in ring A, a ketol side chain in position 17, and other oxygen functions, particularly in positions 11,17,21 and 18. 

Adrenocorticotropic hormone Adrenal cortex Steroid production... 

Sodium Excess. Most of the sodium ingested is excessive, and for the most part it is excreted by the kidneys in combination with bicarbonate or phosphate. However, under some circumstances sodium accumulates in the extracellular fluid and causes edema since the retention of sodium is accompanied by water retention. Such conditions include (1) cardiac or renal failure, (2) adrenal tumors which secrete excessive cortical hormones, and (3) adrenocorticotropic hormone (ACTH) or steroid hormone therapy. In these conditions, individuals benefit from sodium-restricted diets. 

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