growth hormone

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Related to growth hormone releasing h. (GH-RH): somatorelin

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.
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, 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
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 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 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.

so·ma·to·tro·pin

(sō'mă-tō-trō'pin), Do not confuse this word with somatropin.
A protein hormone of the anterior lobe of the pituitary, produced by the acidophil cells, which promotes body growth, fat mobilization, and inhibition of glucose use; diabetogenic when present in excess; a deficiency of somatotropin is associated with a number of types of dwarfism (type III is an X-linked disorder).
[for somatotrophin, fr. somato- + G. trophē nourishment; corrupted to -tropin and reanalyzed as fr. G. tropē, a turning]

growth hormone

n.
1. Any of various natural or synthetic substances that regulate the growth of animals or plants.
2. Abbr. GH Any of such natural substances in vertebrates, consisting of polypeptide hormones that are secreted by the pituitary gland and promote growth of the body, especially by stimulating release of somatomedins. Also called somatotropic hormone, somatotropin.

growth hormone (GH)

a single-chain peptide secreted by the anterior pituitary gland in response to GH-releasing hormone. Its secretion is controlled in part by the hypothalamus. GH promotes protein synthesis in all cells, increases fat mobilization and use of fatty acids for energy, and decreases use of carbohydrate. Growth effects depend on the presence of thyroid hormone, insulin, and carbohydrate. Somatomedins, proteins produced chiefly in the liver, play a vital role in GH-induced skeletal growth. GH cannot cause elongation of long bones after the epiphyses close, however, so stature does not increase after puberty. GH accelerates the transport of specific amino acids into cells, stimulates the synthesis of messenger ribonucleic acid (RNA) and ribosomal RNA, influences the activity of several enzymes, increases the storage of phosphorus and potassium, and promotes a moderate retention of sodium. GH secretion, controlled almost exclusively by the central nervous system, occurs in bursts, with more than half of the total daily amount released during early sleep. Somatostatin, an anterior pituitary regulating hormone produced in the hypothalamus, inhibits GH secretion as well as secretion of insulin and gastrin. A deficiency of GH causes dwarfism; an excess results in gigantism in children or acromegaly in adults. Also called somatotropic hormone, somatotropin. See also acromegaly, dwarfism, gigantism, somatostatin.

growth hormone

Somatotropin A 21.5 kD growth-promoting protein hormone secreted in a pulsatile fashion by the anterior pituitary in response to the hypothalamic regulatory hormones, GHRH and somatostatin; GH influences protein, carbohydrate, fat metabolism. See Recombinant human growth hormone.

so·ma·to·tro·pin

, somatotropic hormone (sōmă-tō-trōpin, -trōpik hōrmōn)
A protein hormone of the anterior lobe of the pituitary, produced by the acidophil cells, which promotes body growth, fat mobilization, and inhibition of glucose utilization; diabetogenic when present in excess; a deficiency of somatotropin is associated with a number of types of dwarfism.
Compare: bioregulator
Synonym(s): growth hormone, pituitary growth hormone.
[fr. somato- + G. trophē nourishment; corrupted to -tropin and reanalyzed as fr. G. tropē, a turning]

growth hormone (GH)

The hormone, somatotropin, produced by the pituitary gland, that controls protein synthesis and hence the process of growth. Excess growth hormone during the normal childhood growth period causes gigantism. Deficiency causes dwarfism. In adult life, excess causes ACROMEGALY. GH is secreted during periods of exercise and stress and for an hour or two after falling asleep. Growth hormone is also produced by breast tissue and in excess by breast cancers. GH encourages cancer cells to metastasize. Somatotropin is available as a commercial product under brand names such as Genotropin, Humatrope, Norditropin, Saizen and Zomacton.

growth hormone or somatotrophic hormone (STH)

a hormone secreted by the anterior PITUITARY GLAND mainly in the growth period, where it stimulates the lengthening of the long bones in TETRAPODS, induces protein synthesis and inhibits INSULIN, thus raising the level of blood sugar. Oversecretion during development produces GIGANTISM but excess later in life gives rise to ACROMEGALY. Deficiency of the hormone results in pituitary DWARFISM.

Growth hormone

A hormone that eventually stimulates growth. Also called somatotropin.
Mentioned in: Pituitary Dwarfism

somatotropin

; growth hormone; GH anterior pituitary hormone that promotes body growth, mobilizes fat stores and inhibits glucose uptake from blood; GH excess prepuberty causes giganticism, and postpuberty causes acromegaly, both of which may be characterized by secondary diabetes (due to effects of excess GH on glucose uptake from blood); underproduction of somatotropin causes a form of dwarfism

growth hormone (grōthˑ hōrˑ·mōn),

n a hormone produced by the pituitary gland; involved in the division of cells and the growth and maintenance of tissues. Also called
GH, HGH, human growth hormone, or
somatotropin.

so·ma·to·tro·pin

, somatotropic hormone (sōmă-tō-trōpin, -trōpik hōrmōn)
Protein hormone of anterior lobe of pituitary, produced by acidophil cells, which promotes body growth, fat mobilization, and inhibition of glucose use.
Synonym(s): growth hormone.
[fr. somato- + G. trophē nourishment; corrupted to -tropin and reanalyzed as fr. G. tropē, a turning]

growth hormone

a substance that stimulates growth, especially the polypeptide hormone secreted by the anterior lobe of the pituitary gland that directly influences protein, carbohydrate and lipid metabolism, and controls the rate of skeletal and visceral growth. The hormone acts on tissues via peripheral factors. Called also somatotropin, somatomedin.

growth hormone release inhibiting h
growth hormone releasing h. (GH-RH)
a hormone elaborated by the hypothalamus, which stimulates the release of growth hormone from the pituitary gland. Called also somatocrinin.
growth hormone-responsive dermatosis
a rare, symmetrical alopecia and hyperpigmentation in dogs. The cause is unknown, but the condition is responsive to bovine or porcine growth hormone. Called also pseudo-Cushing's syndrome, hyposomatotropism, pituitary alopecia.
growth hormone stimulation test
see clonidine stimulation test.

Patient discussion about growth hormone

Q. does the growth hormone have side effects and what are they?

A. Yes, it does, and not a few. They include, among others, pain in the joints, carpal tunnel syndrome, diabetes, pain at the injection site, problems with the thyroid gland, ear problems and many others. You may read more about side effects of growth hormone treatment (called Mecasermin or Somatropin) here: http://www.drugs.com/ppa/mecasermin.html

More discussions about growth hormone
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