adrenocorticotropic hormone

(ədrē`nōkôr'təkōtrŏp`ĭk), polypeptide hormone secreted by the anterior pituitary glandpituitary gland,
small oval endocrine gland that lies at the base of the brain. It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation (see endocrine system).
..... Click the link for more information. . Its chief function is to stimulate the cortex of the adrenal glandadrenal gland
or suprarenal gland
, endocrine gland (see endocrine system) about 2 in. (5.1 cm) long situated atop each kidney. The outer yellowish layer (cortex) of the adrenal gland secretes about 30 steroid hormones, the most important of which are aldosterone and
..... Click the link for more information. to secrete adrenocortical steroids, chief among them cortisonecortisone
, steroid hormone whose main physiological effect is on carbohydrate metabolism. It is synthesized from cholesterol in the outer layer, or cortex, of the adrenal gland under the stimulation of adrenocorticotropic hormone (ACTH).
..... Click the link for more information. . The release of adrenocorticotropic hormone (ACTH), also known as corticotropin, is stimulated by corticotropin-releasing factor (CRF), a secretion of the hypothalamus. ACTH secretion is an excellent example of the regulation of a biological system by a negative-feedback mechanism; high levels of adrenocortical steroids in the blood tend to decrease ACTH release, whereas low steroid levels have the opposite effect. ACTH has the same pharmacologic and clinical effects as cortisone when given intravenously or intramuscularly; however, it has no value when applied externally and cannot be taken orally since it is deactivated by digestive enzymes. The action of ACTH is contingent upon normally functioning adrenal glands and is therefore useless in disorders caused by adrenal insufficiency, e.g., as replacement therapy where both adrenal glands have been removed.

Adrenocorticotropic Hormone

(ACTH; also corticotropin), a hormone produced by the anterior lobe of the hypophysis. It stimulates the function of the cortex of the adrenal glands (the production of corticoids—in particular, hydrocortisone) and thereby contributes to the normal course of metabolic processes and to the increased resistance of human and animal organisms to the effects of unfavorable conditions.

ACTH is a peptide chain consisting of 39 amino acid residues and has a molecular weight of about 4,500. Its biological activity is due to the 24 amino acid residues that are closest to the amine end of the molecule, while the remaining 15 define the species characteristics and immunological properties of the hormone. In addition to its primary effects on the adrenal glands, ACTH also exhibits fat-mobilizing and melanocyte-stimulating activity. When the defense mechanisms of the body must be mobilized (during trauma, infection, stress situations, and so forth), increased amounts of ACTH are secreted into the blood.

The secretion of ACTH by the hypophysis is controlled by the hypothalamus. The regulatory influences from the hypothalamus are transmitted to the hypophysis by a neurohumoral substance, probably a peptide, found in the hypothalamus. This substance is called corticotropin releasing factor, or CRF.

ACTH is used as a hormonal preparation in the treatment of adrenocortical insufficiency caused by hypophyseal disorders, as well as in the treatment of rheumatism, polyarthritis, gout, bronchial asthma, eczema and other allergies, and other diseases. ACTH for medical use is obtained from the hypophyses of cattle. ACTH has also been synthesized; these preparations, which differ structurally from natural ACTH, have a higher biological activity.

REFERENCES

Pankov, Iu. A. “Khimiia AKTG i mekhanizm reguliatsii ego sekretsii.” Uspekhi sovremennoi biologii, 1959, vol. 47, no. 3.
Gorizontov, P. D., and T. N. Protasova. Rol’ AKTG i kortikos-teroidov v patologii. Moscow, 1968.
Schwyzer, R. “Chemistry and metabolic action of nonsteroid hormones.” Annual Review of Biochemistry, 1964, vol. 33, pp. 259–85.

IU. A. PANKOV

adrenocorticotropic hormone

[ə¦drēn·ō′kȯrd·ə·kō′träp·ik ′hȯr‚mōn] (biochemistry) The chemical secretion of the adenohypophysis that stimulates the adrenal cortex. Abbreviated ACTH. Also known as adrenotropic hormone.

adrenocorticotropic hormone

hormone

[hor´mōn] a chemical transmitter substance produced by cells of the body and transported by the bloodstream to the cells and organs on which it has a specific regulatory effect. adj., adj hormo´nal. Hormones act as chemical messengers to body organs, stimulating certain life processes and retarding others. Growth, reproduction, control of metabolic processes, sexual attributes, and even mental conditions and personality traits are dependent on hormones.
Hormones are produced by various organs and body tissues, but mainly by the endocrine glands, such as the pituitary, thyroid, and gonads (testes and ovaries). Each gland apparently synthesizes several kinds of hormones; the adrenal glands alone produce more than 25 varieties. The total number of hormones is still unknown, but each has its unique function and its own chemical formula. After a hormone is discharged by its parent gland into the capillaries or the lymph, it may travel a circuitous path through the bloodstream to exert influence on cells, tissues, and organs (target organs) far removed from its site of origin.
One of the best-known endocrine hormones is insulin, a protein manufactured by the beta cells of the islands of Langerhans in the pancreas that is important in carbohydrate metabolism. Other important hormones are thyroxine, an iodine-carrying amino acid produced by the thyroid gland; cortisone, a member of the steroid family from the adrenal glands; and the sex hormones, estrogen from the ovaries and androgen from the testes. Certain hormone substances can be synthesized in the laboratory for treatment of human disease. Animal hormones can also be used, as endocrine hormones are to some extent interchangeable among species. Extracts from the pancreas of cattle, for example, enabled diabetes sufferers to live normal lives even before the chemistry of insulin was fully understood.
Endocrine hormone synthesis and secretion is controlled and regulated by a closed-loop system. Negative feedback loops maintain optimal levels of each hormone in the body. If there are abnormally high levels of a hormone in the blood, feedback to the gland responsible for its production inhibits secretion. If there are abnormally low levels, the gland is stimulated to step up production and secretion. In this way a homeostatic balance is maintained. (See also endocrine glands.)adrenocortical hormone 1. any of the corticosteroids secreted by the adrenal cortex, the major ones being the glucocorticoids and mineralocorticoids, and including some androgens, progesterone, and estrogens.2. corticosteroid.adrenocorticotropic hormone (ACTH) corticotropin.adrenomedullary h's substances secreted by the adrenal medulla, including epinephrine and norepinephrine.androgenic hormone androgen.anterior pituitary hormone any of the protein or polypeptide hormones secreted by the anterior lobe of the pituitary gland" >pituitary gland, including growth hormone, thyrotropin, prolactin, follicle-stimulating hormone, luteinizing hormone, melanocyte-stimulating hormone, and corticotropin.antidiuretic hormone (ADH) vasopressin.corpus luteum hormone progesterone.cortical hormone corticosteroid.corticotropin-releasing hormone (CRH) a neuropeptide secreted by the median eminence of the hypothalamus that binds to specific receptors on the corticotroph cells of the anterior pituitary and stimulates the secretion of corticotropin.ectopic h's those secreted by tumors of nonendocrine tissues but having the same physiologic effects as their normally produced counterparts. It is not known exactly how the synthesis and secretion of endocrine hormones from nonendocrine tissues occurs. Most of these tumors are derived from tissues that have a common embryonic origin with endocrine tissues. When the cells undergo neoplastic transformation, they can revert to a more primitive stage of development and begin to synthesize hormones.
Ectopic hormones present serious problems for patients and add to the complexity of caring for those with certain kinds of neoplastic diseases. These hormones do not respond to the feedback mechanisms that regulate normal hormonal production; hence, surgery and destruction of the tumorous tissue by radiation and chemotherapy are the treatments of choice.estrogenic hormone estrogen.follicle-stimulating hormone (FSH) one of the gonadotropins of the anterior pituitary, which stimulates the growth and maturity of graafian follicles in the ovary, and stimulates spermatogenesis in the male.follicle-stimulating hormone and luteinizing hormone–releasing hormone (FSH/LH-RH) luteinizing hormone–releasing hormone.follicle-stimulating hormone–releasing hormone (FSH-RH) luteinizing hormone–releasing hormone.gonadotropic hormone gonadotropin.gonadotropin-releasing hormone (Gn-RH) luteinizing hormone–releasing hormone.growth hormone (GH) any of several related polypeptide hormones secreted by the anterior lobe of the pituitary gland that directly influence protein, carbohydrate, and lipid metabolism and control the rate of skeletal and visceral growth; their secretion is in part controlled by the hypothalamus. It is used pharmaceutically as somatrem and somatropin. Called also somatotrophin, somatotropin, and somatotrophic or somatotropic hormone.growth hormone release–inhibiting hormone somatostatin.growth hormone–releasing hormone (GH-RH) a neuropeptide elaborated by the median eminence of the hypothalamus that binds to specific receptors on the somatotroph cells of the anterior pituitary and stimulates the secretion of growth hormone.interstitial cell–stimulating hormone luteinizing hormone.lactation hormone (lactogenic hormone) prolactin.local hormone a substance with hormone like properties that acts at an anatomically restricted site; most are rapidly degraded. Called also autacoid and autocoid.luteinizing hormone (LH) a gonadotropin of the anterior pituitary gland, acting with follicle-stimulating hormone to cause ovulation of mature follicles and secretion of estrogen by thecal and granulosa cells of the ovary; it is also concerned with corpus luteum formation. In the male, it stimulates development of the interstitial cells of the testes and their secretion of testosterone. Called also interstitial cell–stimulating hormone.luteinizing hormone–releasing hormone (LH-RH) a decapeptide hormone of the hypothalamus, which stimulates the release of follicle-stimulating hormone and luteinizing hormone from the pituitary gland; it can be used in the differential diagnosis of hypothalamic, pituitary, and gonadal dysfunction. Called also follicle-stimulating hormone–releasing hormone, follicle-stimulating hormone and luteinizing hormone–releasing hormone, and gonadotropin-releasing hormone.melanocyte-stimulating hormone (MSH) a substance from the anterior pituitary gland of certain other animals but not humans; it influences the formation or deposition of melanin in the body and pigmentation of the skin.neurohypophyseal h's those stored and released by the neurohypophysis, i.e., oxytocin and vasopressin.parathyroid hormone (PTH) a polypeptide hormone secreted by the parathyroid glands that influences calcium and phosphorus metabolism and bone formation.placental h's hormones secreted by the placenta, including chorionic gonadotropin, and other substances having estrogenic, progestational, or adrenocorticoid activity.progestational hormone 1. progesterone.2. progestational agent.prolactin-inhibiting hormone a hormone released by the hypothalamus that inhibits the secretion of prolactin by the anterior pituitary gland.prolactin-releasing hormone any of various hormones elaborated by the hypothalamus that stimulate the release of prolactin by the anterior pituitary gland. Most such activity is exerted by vasoactive intestinal polypeptide, although in humans hormone" >thyrotropin-releasing hormone can also have this action. sex h's see sex hormones.somatotrophic hormone (somatotropic hormone) growth hormone.somatotropin release–inhibiting hormone somatostatin.somatotropin-releasing hormone (SRH) growth hormone–releasing hormone.steroid h's hormones that are biologically active steroids; they are secreted by the cortex" >adrenal cortex, testis, ovary, and placenta and include the progestational agents, glucocorticoids, mineralocorticoids, androgens, and estrogens. They act by binding to specific receptors to form complexes, which then enhance or inhibit the expression of specific genes.thyroid h's see thyroid hormones.thyroid-stimulating hormone (TSH) thyrotropin.thyrotropin-releasing hormone (TRH) a tripeptide hormone of the hypothalamus, which stimulates release of thyrotropin from the pituitary gland. In humans, it also acts as a prolactinreleasing factor. It is used in the diagnosis of mild hyperthyroidism and Graves disease, and in differentiating between primary, secondary, and tertiary hypothyroidism.

a·dre·no·cor·ti·co·tro·pic hor·mone (ACTH),

the hormone of the anterior lobe of the hypophysis that governs the nutrition and growth of the adrenal cortex, stimulates it to functional activity, and shows extraadrenal adipokinetic activity; it is a polypeptide containing 39 amino acids, but exact structure varies from one species to another; sometimes prefixed by α to distinguish it from β-corticotropin. The first 13 amino acids at the N-terminal region are identical to α-melanotropin. Synonym(s): adrenocorticotropin, adrenotropic hormone, adrenotropin, corticotropic hormone, corticotropin (1)

adrenocorticotropic hormone

also

adrenocorticotrophic hormone

n. ACTH.

POMC

A gene on chromosome 2p23 that encodes proopiomelanocortin, the melanocortin family of hormones, which include alpha-, beta- and gamma-melanocyte stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH). The melanocortins bind to the melanocortin receptors, a group of five G protein-coupled receptors (MC1R to MC5R) which are involved in a wide range of physiological functions, including pigmentation, energy homeostasis, inflammation, immunomodulation, steroidogenesis and temperature control.
Molecular pathology
Defects of POMC are associated with susceptibility to obesity and proopiomelanocortin deficiency.

ad·re·no·cor·ti·co·tro·pic hor·mone

(ACTH) (ă-drē'nō-kōr'ti-kō-trō'pik hōr'mōn) The hormone of the anterior lobe of the hypophysis that governs the nutrition and growth of the cortex of the suprarenal gland and stimulates it to functional activity; also possesses extraadrenal adipokinetic activity.
Synonym(s): adrenotropin, corticotropin.

Adrenocorticotropic hormone (ACTH)

Also called corticotropin, this hormone is produced by the pituitary gland to stimulate the adrenal cortex to release various corticosteroid hormones.Mentioned in: Cortisol Tests, Cushing's Syndrome

ad·re·no·cor·ti·co·tro·pic hor·mone

(ACTH) (ă-drē'nō-kōr'ti-kō-trō'pik hōr'mōn) Hormone of anterior lobe of hypophysis that governs nutrition and growth of the adrenal cortex, stimulates it to functional activity.
Synonym(s): corticotropic hormone.

adrenocorticotropic hormone

adrenocorticotropic hormone

ACTH

adrenocorticotropic hormone

adrenocorticotropic hormone

Adrenocorticotropic Hormone

REFERENCES

adrenocorticotropic hormone

adrenocorticotropic hormone

hormone

a·dre·no·cor·ti·co·tro·pic hor·mone (ACTH),

adrenocorticotropic hormone

adrenocorticotrophic hormone

POMC

ad·re·no·cor·ti·co·tro·pic hor·mone

Adrenocorticotropic hormone (ACTH)

ad·re·no·cor·ti·co·tro·pic hor·mone

adrenocorticotropic hormone

Synonyms for adrenocorticotropic hormone

noun a hormone produced by the anterior pituitary gland that stimulates the adrenal cortex

Synonyms

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