Adrenal cortex hormones produced

Corticotropin (ACTH) is an anterior pituitary hormone that stimulates the adrenal cortex to produce and secrete adrenocortical hormones, primarily the glucocorticoids. 

Adrenal hormone production is controlled by the hypothalamus and pituitary gland. Corticotropin-releasing hormone (CRH) is secreted by the hypothalamus and stimulates secretion of adrenocorticotropic hormone (ACTH), also known as corticotropin from the anterior pituitary. ACTH, in turn, stimulates the adrenal cortex to produce cortisol. When sufficient or excessive cortisol levels are reached, a negative feedback is exerted on the secretion of CRH and ACTH, thereby decreasing overall cortisol production. The control of adrenal androgen synthesis also follows a similar negative-feedback mechanism. 

In relatively recent years, it has become clear that under-nntrition of mother leads to low birth weight of the baby and this can increase the risk of development of degenerative disease in later life, e.g. hypertension, obesity, type 2 diabetes. One hypothesis is that the foetus adapts meta-bolically to deficiencies by increasing the number of cells in organs that perform specific functions that can overcome the deficiency, e.g. an increase in the number of liver cells that carry out gluconeogenesis, an increase in cells in the adrenal cortex to produce more of the chronic stress hormone, cortisol. These changes are carried over into adnlthood which can lead to an inadequate response of the liver to insulin so that insulin resistance develops. So far, however, it is unclear whether deficiencies in specific nntrients or undemutrition per se are responsible for snch changes (Chapter 15). 

I. Replacement therapy. The adrenal cortex (AC) produces the glucocorticoid cortisol (hydrocortisone) and the mine-ralocorticoid aldosterone. Both steroid hormones are vitally important in adaptation responses to stress situations, such as disease, trauma, or surgery. Cortisol secretion is stimulated by hypophyseal ACTH, aldosterone secretion by angiotensin 11 in particular (p. 124). In AC failure (primary AC insuffiency ... 

All of Ihese hormones arc synthesized from cholesterol in the adrenal cortex, by ait extended scries of reaelions. which include many related compounds. Although these hormones have widespread effects throughout the organism, their primary mechanism is not known, so that many of the effects may be indirect. Much of the knowledge t l their action arises from studies of insufficiency or hyperactivity of the adrenal cortex, which produces a wide variety of pathological condilioiis. See Table I. 

The primary function of AC. TH is the stimulation of the adrenal cortex to produce its hormones, which have already been discussed. This is evideni from the therapeutic effect of administration of ACTH. which is closely similar to that of Ihese hormones, so that if ihe action of only one of them is sought, its administration is preferable, Moreover. ACTH stimulates secretion of the androgenic substances mentioned as produced by the adrenal cortex. 

ACTH stimulates the adrenal cortex to produce glucocorticoids, mineralocorticoids, and androgens. ACTH increases the activity of cholesterol esterase, the enzyme that catalyzes the rate-limiting step of steroid hormone production cholesterol - pregnenolone. ACTH also stimulates adrenal hypertrophy and hyperplasia. When given chronically in pharmacologic doses, corticotropin causes increased skin pigmentation. 

The adrenal cortex (AC) produces the glucocorticoid cortisol (hydrocortisone) in the zona fasciculata and the mineralocorticoid aldosterone in the zona glomerulosa. Both steroid hormones are vitally important in adaptation responses to stress situations, such as disease, trauma, or surgery. Cortisol secretion is stimulated by hypophyseal ACTH aldosterone secretion by angiotensin II in particular (p. 128). In AC failure (primary adrenocortical insuf ciency, Addison disease), both cortisol and aldosterone must be replaced when ACTH production is deficient (secondary adrenocortical insuf ciency), cortisol alone needs to be replaced. Cortisol is effective when given orally (30 mg/day, 2/3 a.m 1 /3 p.m.). In stress situations, the dose is raised 5- to 10-fold. Aldosterone is poorly effective via the oral route instead, the mineralocorticoid fludrocortisone (0.1 mg/day) is given. 

Hypoadrenocorticism A failure of the adrenal cortex to produce glucocorticoid (and in some cases mineralocorticoid) hormones. 

Glucocorticoid hormones promote gluconeogenesis and, in pharmacological doses, suppresses inflammation reactions, / -corticotropin is secreted from the anterior pituitary, and it stimulates the adrenal cortex to produce glucocorticoids and mineralocorticoids, which in turn act on a number of tissues. 

Most pituitary hormones act on endocrine glands that occupy an intermediate, or secondary, position in the hierarchy, stimulating them to produce hormones that exert the ultimate actions on target tissues. Pituitary hormones that act on other endocrine glands are called tropic hormones or tropins. An example is adrenal corticotropic hormone (ACTH), also called / -corticotropin (see here also). This peptide is secreted from the anterior pituitary, and it stimulates the adrenal cortex to produce glucocorticoids and mineralocorticoids, which in turn act on a number of tissues. 

Cushing s disease, the cause of Corti Solemia s current problems, results from prolonged hypersecretion of ACTH from a benign pituitary tumor. ACTH stimulates the adrenal cortex to produce cortisol, and blood levels of this steroid hormone rise. 

It is used in medicine as a powerful anti-inflammatory and anti-allergic agent, but it has serious side effects on continued use. Many related compounds (corticosteroids) are used in medicine. ACTH is a protein hormone that stimulates the adrenal cortex to produce the corticosteroids. It has molecular mass about 3,500 d ox ACTH contains 39 amino-acid residues. It is used to some extent in medicine. 

Cortisone is a hormone produced by the cortex of the adrenal glands. As with other adrenal corticoid steroids, administration of cortisone leads to an increased deposition of liver glycogen. Tt can remove features of rheumatoid arthritis, but does not check the underlying disease it is used in various diseases of the eye, and is an antiallergic and anlifibroplastic agent. 

Control of secretion of anterior pituitary hormones also includes inhibition by hormones produced by target organs. For example, CRH stimulates the anterior pituitary to secrete ACTH, which in turn stimulates the adrenal cortex to secrete corticosteroids. Corticosteroids then feed back to inhibit the secretion of ACTH. Feedback mechanisms are important for the control of most hormones. For example, insulin (qv) secretion from the pancreas increases in response to increased blood glucose resulting from ingestion of a meal. Insulin increases tissue uptake and metaboHsm of glucose, which lowers blood glucose and in turn reduces insulin secretion. 

The adrenal cortex produces steroidal hormones that are associated with carbohydrate, fat, and protein metabolism, electrolyte balance, and gonadal functions (58). One of these, cortisone [53-06-5] ( ) demonstrated a remarkable ability to relieve the symptoms of inflammatory conditions... 

List the hormones produced by the pituitary gland and the adrenal cortex. 

This section of the chapter discusses FSH, LH, GH, and ACTH. FSH and LH are called gonadotropins because they influence the gonads (the organs of reproduction). GH, also called somatotropin, contributes to the growth of the body during childhood, especially the growth of muscles and bones. ACTH is produced by the anterior pituitary and stimulates the adrenal cortex to secrete the corticosteroids. The anterior pituitary hormone, TSH, is discussed in Chapter 51. Prolactin, which is also secreted by the anterior pituitary, stimulates the production of breast milk in the postpartum patient Additional functions of prolactin are not well understood. Prolactin is the only anterior pituitary hormone that is not used medically. 

This section of the chapter discusses the hormones produced by the adrenal cortex or the adrenocortical hormones, which are the glucocorticoids and mineralocorticoids. These hormones are essential to life and influence many organs and structures of the body. The glucocorticoids and mineralocorticoids are collectively called corticosteroids. 

Aldosterone A hormone produced in and secreted by the zona glomerulosa of the adrenal cortex. Aldosterone acts on the kidneys to reabsorb sodium and excrete potassium. It is also a part of the renin-angiotensin-aldosterone system, which regulates blood pressure and blood volume. 

Steroid hormones are produced by the adrenal cortex, testes, ovaries, and placenta. Synthesized from cholesterol, these hormones are lipid soluble therefore, they cross cell membranes readily and bind to receptors found intracellularly. However, because their lipid solubility renders them insoluble in blood, these hormones are transported in the blood bound to proteins. Furthermore, steroid hormones are not typically preformed and stored for future use within the endocrine gland. Because they are lipid soluble, they could diffuse out of the cells and physiological regulation of their release would not be possible. Finally, steroid hormones are absorbed easily by the gastrointestinal tract and therefore may be administered orally. 

A trophic hormone acts on another endocrine gland to stimulate secretion of its hormone. For example, thyrotropin, or thyroid-stimulating hormone (TSH), stimulates the secretion of thyroid hormones. Adrenocorticotropin, or adrenocorticotropic hormone (ACTH), stimulates the adrenal cortex to secrete the hormone cortisol. Both trophic hormones are produced by the pituitary gland in fact, many trophic hormones are secreted by the pituitary. The pituitary gland is sometimes referred to as the "master gland" because its hormones regulate the activity of other endocrine glands. 

Steroid hormones are produced by only two tissue types, the adrenal cortex and the gonads. A summary of the steroid hormones is given in Table 4.2. Steroid hormones are synthesized from cholesterol (Figure 4.2). This sterol lipid may itself be synthesized within the steroidogenic cell or it may be delivered to the cell by circulating lipoprotein complexes such as low density lipoprotein (LDL) or high density lipoprotein (HDL). 

Angiotensin II has two effects first, as a vasoconstrictor acting via receptors on vascular smooth muscle cells, and second, it stimulates the adrenal cortex gland to produce aldosterone (a mineralocorticoid steroid hormone, see Chapter 4). Aldosterone promotes the reabsorption of sodium from the renal tubule into the bloodstream and the resulting increase in osmolality (osmotic potential) of the blood causes water reabsorption in the nephrons. The outcome is an increase in blood volume and, therefore, pressure which inhibits (by negative feedback) further renin secretion from the JGA. 

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