Inhibiting hormone

Tumors derived from hormone sensitive tissues may remain hormone dependent and are then amenable to therapeutic approaches with hormonal agents. These include hormones with opposing (apoptotic) action, hormone antagonists, and agents that inhibit hormone synthesis. 

In contrast to the posterior pituitary lobe, the anterior pituitary lobe is under the control of several releasing and inhibiting hormones secreted from the hypothalamus via a portal vein system. The anterior pituitary lobe, in turn, synthesizes and secretes six major hormones. Figure 43-1 summarizes the physiologic mediators and effects of each of these hormones. 

Somatostatin Analog (Growth Hormone-Inhibiting Hormone)... 

GHIH growth hormone-inhibiting hormone or somatostatin... 

Paraneoplastic syndromes are clinical syndromes owing to nonmetastatic systemic effects of cancer. Tumors make and secrete biologically active products that can stimulate or inhibit hormone production, autoimmunity, immune complex production, or immune suppression. Lung cancer, particularly small cell lung cancer, is associated with a high rate of paraneoplastic... 

Somatostatin A growth hormone-inhibiting hormone that stops production of growth hormone from the anterior pituitary. 

BIO. Ben-Jonathan, N Dopamine A prolactin-inhibiting hormone. Endocr. Rev. 6,564-589 (1985). 

Located in close proximity to the primary capillary plexus in the hypothalamus are specialized neurosecretory cells. In fact, the axons of these cells terminate on the capillaries. The neurosecretory cells synthesize two types of hormones releasing hormones and inhibiting hormones (see Table 10.2). Each of these hormones helps to regulate the release of a particular hormone from the adenohypophysis. For example, thyrotropin-releasing hormone produced by the neurosecretory cells of the hypothalamus stimulates secretion of thyrotropin from the thyrotrope cells of the adenohypophysis. The hypo-thalamic-releasing hormone is picked up by the primary capillary plexus travels through the hypothalamic-hypophyseal portal veins to the anterior pituitary leaves the blood by way of the secondary capillary plexus and exerts its effect on the appropriate cells of the adenohypophysis. The hypophyseal hormone, in this case, thyrotropin, is then picked up by the secondary capillary plexus, removed from the pituitary by the venous blood, and delivered to its target tissue. 

Releasing and inhibiting hormones (GnRH, TRH, CRH, PRF, PIH, GHRH, GHIH)... 

The release of prolactin from the adenohypophysis is normally inhibited by prolactin-inhibiting hormone (PIH, dopamine) from the hypothalamus. Prolactin secretion is also controlled by prolactin-releasing factor (PRF). The release of PRF from the hypothalamus is mediated by reflexes elicited by suckling and breast stimulation. 

The hypothalamus is part of the brain. It is an important regulatory centre and produces a range of peptide-releasing and release-inhibiting hormones, which control the secretory activity of the pituitary. 

Produces releasing hormones, e.g., for corticotropin, growth hormone, gonadotropin, thyrotropin Produces inhibiting hormones, e.g., for the growth hormone... 

Prolactin secretion is under the inhibitory control of hypothalamus through prolactin inhibiting hormone (PRIH) which is a dopamine and acts on pituitary lactotrope receptor. 

Agents which inhibit hormone synthesis Propyl thiouracil 50-100 mg/day (initial) and maintained at 20-30 mg/day... 

II. Agents which inhibit iodide trapping Thiocyanates, perchlorates and nitrates III. Agents which inhibit hormone release ... 

Iodine inhibits hormone release. They inhibit organification and hormone release and also decrease the size and vascularity of hyperplastic gland on regular administration. Peak antithyroid affect is seen in two weeks after which thyrotoxicosis may reoccur. It is well absorbed orally and crosses the placental barrier. 

Hypothalamic hormone Human growth hormonereleasing hormone and -inhibiting hormone (somatostatin)... 

A 56-residue peptide, which is formed from the 10-kDa precursor to GnRH, inhibits secretion of prolactin.75 Inhibition of FSH release is accomplished by feedback inhibition. Hormones known as inhibins are produced in the gonads and act to inhibit release of FSH from the pituitary.76... 

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