Synthesized hormones

A hormone synthesized in the pineal gland Certain mental disorders are be lieved to be related to sero tonin levels in the brain )... 

Grignard reagents add to diketene ia the presence of cobalt iodide [15238-00-3] C0I2, or palladium [440-05-3] to give 3-methylenecarboxyhc acids, used ia terpenoid and hormone syntheses, as well as monomers for radical copolymers (116,117) (see Hormones Terpenoids). 

Anemia may occur in patients with chronic renal failure as tlie result of the inability of the kidney to produce erythropoietin. Erythropoietin is a glycoprotein hormone synthesized mainly in the kidneys and used to stimulate and regulate the production of erythrocytes or red blood cells (RBCs). Failure to produce the needed erythrocytes results in anemia Two examples of drug used to treat anemia associated with chronic renal failure are epoetin alfa (Epogen) and darbepoetin alfa (Aranesp). 

The estrogens are a family of hormones synthesized in a variety of tissues. 17P-Estradiol is the primary estrogen of ovarian origin. In some species, estrone, synthesized in numerous tissues, is more abundant. In pregnancy, relatively more estriol is produced, and this comes from the placenta. The general pathway and the subcellular localization of the enzymes involved in the early steps of estradiol synthesis are the same as those involved in androgen biosynthesis. Features unique to the ovary are illustrated in Figure 42-7. 

The thyroid gland is a butterfly-shaped structure lying over the ventral surface of the trachea just below the larynx. This gland produces two classes of hormones synthesized by two distinct cell types ... 

In order to make adjustments in the water load, the reabsorption of the remaining 20% of the filtered water from the distal tubule and the collecting duct is physiologically controlled by antidiuretic hormone (ADH), also referred to as vasopressin. Antidiuretic hormone, synthesized in the hypothalamus and released from the neurohypophysis of the pituitary gland, promotes the... 

The cholesterol required for biosynthesis of the steroid hormones is obtained from various sources, it is either taken up as a constituent of LDL lipoproteins (see p. 278) into the hormone-synthesizing glandular cells, or synthesized by glandular cells themselves from acetyl-CoA (see p. 172). Excess cholesterol is stored in the form of fatty acid esters in lipid droplets. Hydrolysis allows rapid mobilization of the cholesterol from this reserve again. 

Epinephrine is a hormone synthesized in the adrenal glands from tyrosine (see p. 352). Its release is subject to neuronal control. This emergency hormone mainly acts on the blood vessels, heart, and metabolism. It constricts the blood vessels and thereby increases blood pressure (via ai and a2 receptors) it increases cardiac function (via P2 receptors) it promotes the degradation of glycogen into glucose in the liver and muscles (via P2 receptors) and it dilates the bronchia (also via P2 receptors). 

Pharmacology Pramlintide is a synthetic analog of human amylin, a naturally occurring neuroendocrine hormone synthesized by pancreatic beta cells that contributes to glucose control during the postprandial period. 

Human growth hormone (hGH, somatotrophin Figure 8.11) is a polypeptide hormone synthesized in the anterior pituitary. It promotes normal body growth and lactation and influences various aspects of cellular metabolism. 

T FIGURE 10-19 Steroids derived from cholesterol. Testosterone, the male sex hormone, is produced in the testes. Estradiol, one of the female sex hormones, is produced in the ovaries and placenta. Cortisol and aldosterone are hormones synthesized in the cortex of the adrenal gland they regulate glucose metabolism and salt excretion, respectively. Prednisolone and prednisone are synthetic steroids used as antiinflammatory agents. 

Catecholamines produced in the brain and in other neural tissues function as neurotransmitters, but epinephrine and norepinephrine are also hormones, synthesized and secreted by the adrenal glands. Like the peptide hormones, catecholamines are highly concentrated within secretory vesicles and released by exocytosis, and they act through surface receptors to generate intracellular second messengers. They mediate a wide variety of physiological responses to acute stress (see Table 23-6). 

The hypothalamic control of the posterior pituitary is quite different than that of the anterior and intermediate lobes. Specific neurons have their cell bodies in certain hypothalamic nuclei. Cell bodies in the paraventricular nuclei manufacture oxytocin, whereas the supraoptic nuclei contain cell bodies that synthesize ADH. The axons from these cells extend downward through the infundibulum to terminate in the posterior pituitary. Hormones synthesized in the hypothalamic cell bodies are transported down the axon to be stored in neurosecretory granules in their respective nerve terminals (located in the posterior pituitary). When an appropriate stimulus is present, these neurons fire an action potential, which causes the hormones to release from their pituitary nerve terminals. The hormones are ultimately picked up by the systemic circulation and transported to their target tissues. 

Epinephrine A hormone synthesized primarily in the adrenal medulla, mimicking the peripheral effects of norepinephrine. Epinephrine is involved in the sympathetic nervous system response to stress and is especially effective in stimulating cardiovascular function (SYN adrenaline). 

There emerges a very complex picture of three hormones synthesized and secreted at variable rates, competing for carrier binding proteins, presumed receptor proteins, epoxide hydratase and carboxyl esterase enzymes (35,36). It is possible experimentally to measure tEe timing of critical periods for larval determination and to measure total levels of JH at these critical periods although both measurements involve extreme difficulty. Approaches to this were described recently by G.B. Staal (3 7) using third instar larvae of the tobacco hornworm moth, Manduca sexta, which were allatectomized and raised on JH impregnated diets as an experimentally reproducible method of JH therapy. 

Some of the most important physiological steroids are the adrenocortical hormones, synthesized by the adrenal cortex. Most of these hormones have either a carbonyl group or a hydroxyl group at Cl 1 of the steroid skeleton. The principal adrenocortical hormone is cortisol, used for the treatment of inflammatory diseases of the skin (psoriasis), the joints (rheumatoid arthritis), and the lungs (asthma). Figure 25-10 compares the structure of natural cortisol with two synthetic corticoids fluocinolone acetonide, a fluori-nated synthetic hormone that is more potent than cortisol for treating skin inflammation and beclomethasone, a chlorinated synthetic hormone that is more potent than cortisol for treating asthma. 

Insulin and glucagon are polypeptide hormones synthesized in, and secreted by, the pancreas. Insulin is produced by the / cells of the pancreas, and glucagon by the a cells. The secretion of either of these hormones depends on the blood glucose concentration above 4.5-5.5 mM (80-100 mg/100 mL) of glucose, insulin is secreted, but below 4.5 mA/ (80 mg/100 mL). glucagon is secreted. 

Bertherat J, Dournaud P, Berod A, Normand E, Bloch B, Rostene W, Kordon K, Epelbaum J (1992) Growth hormone-releasing hormone-synthesizing neurons are a subpopulation of somatostatin receptor-labeled cells in the rat arcuate nucleus a combined in situ hybridization and receptor light microscopic radioautographic study. Neuroendocrinology 56 25-31. 

Q1 Each adrenal gland is composed of an outer cortex and an inner medulla. The cortex consists of three layers where several steroid hormones, synthesized from cholesterol, are produced and secreted. The outer layer of the cortex, the zona glomerulosa, produces the mineralocorticoid aldosterone. The zona fasciculata lies under this layer and, together with the inner layer, the zona reticularis, secretes glucocorticoids, mainly cortisol, corticosterone and androgens. 

A Peptide Hormone Synthesized in Liver, Hepcidin, Coordinates Mammalian Iron Physiology... 

Still etal have reported a highly stereoselective synthesis of the alcohol ( 4) which has been previously converted into the Cis Cecropia Juvenile Hormone (Scheme 3). The key step in this synthesis involves the recently described [2,3] sigmatropic rearrangement of the dilithio dianion derived from (13). Full details of the previously reported Ci and Cig Cecropia Juvenile Hormone syntheses have been published."... 

CCK is a gut hormone synthesized by the i cells of the small intestine. This hormone occurs in a variety of sizes versions of 58,39,33, and 8 amino adds are found in the bloodstream. Whether the slight differences in effects of larger or smaller versions of CCIC are physiologically important has not been dearly established, Because of its chemical simplicity, the 3-ammo acid version has been used in many research studies,... 

The pituitary gland is involved in feedback regulation of thyroid activity High levels of T4 in the bloodstream result in inhibition of TSH secretion. Low levels of T4 result in an increase in TSH secretion. These effects are dependent on the conversion of T4 to T3 within the pituitary, fhe activity of the pituitary is controlled by thyrotropin-releasing hormone (TRH), a hormone synthesized in the hypothalamus. TRH is a tripeptide with the structure pyroglutamate-histidine-proline-NH . Note the C-terminal amide group, which is required for the activity of many peptide hormones. TRH stimulates the synthesis and secretion of TSH. Apparently TRH is involved in regulating the sensitivity of the pituitary to the inhibitory feedback control mechanism mentioned earlier. 

Hormone synthesis can be altered by changes in the size and population of hormone producing cells, modification of the activity of hormone synthesizing enzymes, lack of precursors, or interference with enzyme cofactors such as divalent cations. Eor example, the fungicide fenarimol inhibits the enzyme aromatase, which converts testosterone to estrogen. Exposures to acrylamide monomer induce changes in the volume of cellular components in the thyroid... 

Sands SA, Morilak DA. Expression of a1D adrenergic receptor messenger RNA in oxytocin- and corticotropin-releasing hormone-synthesizing neurons in the rat paraventricular nucleus. Neuroscience 1999 91 639-649. 

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