Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Growth hormone (GH)-releasing peptides (GHRPs) are synthetic peptides that strongly induce GH release. GHRPs act via a specific receptor, the GHRP receptor (GHSR), of which ghrelin is a natural ligand. GHRPs also induce adrenocorticotropic hormone (ACTH) release in healthy subjects. GHRPs or ghrelin stimulate ACTH release via corticotropin-releasing factor (CRF) and arginin vasopressin in the hypothalamus. Stress-activated CRF neurons are suppressed by glucocorticoids in the hypothalamic paraventricular nucleus (PVN), while CRF gene is up-regulated by glucocorticoids in the PVN cells without the influence of input neurons. However, little is known about the regulation of ghrelin and GHSR type 1a (GHSR1a) genes by glucocorticoids in PVN cells. To elucidate the regulation of ghrelin and GHSR gene expression by glucocorticoids in PVN cells, here we used a homologous PVN neuronal cell line, hypothalamic 4B, because these cells show characteristics of the parvocellular neurons of the PVN. These cells also express ghrelin and GHSR1a mRNA. Dexamethasone increased ghrelin mRNA levels. A potent glucocorticoid receptor antagonist, RU-486, significantly blocked dexamethasone-induced increases in ghrelin mRNA levels. Dexamethasone also significantly stimulated GHSR1a mRNA and protein levels. Finally, ghrelin increased CRF mRNA levels, as did dexamethasone. Incubation with both dexamethasone and ghrelin had an additive effect on CRF and ghrelin mRNA levels. The ghrelin-GHSR1a system is activated by glucocorticoids in the hypothalamic cells.
 ...
PMID:Dexamethasone stimulates the expression of ghrelin and its receptor in rat hypothalamic 4B cells. 2212 Aug 31

Cushing's syndrome (CS) is a heterogeneous disorder of diverse etiologies, leading to cortisol excess. Endogenous CS is caused by tumors secreting adrenocorticotropin (ACTH) (either eutopically or ectopically), cortisol, or very rarely corticotropin-releasing hormone (CRH). Definitive therapy of endogenous CS optimally involves tumor resection. Indications for medical therapy include acutely ill patients in preparation for surgery, those for whom surgery is not indicated (such as patients with unknown tumor location or unresectable lesions, and patients unfit for surgery for medical reasons), or patients who remain hypercortisolemic postoperatively. In the current article, the published literature has been reviewed to summarize data on medical therapies used in CS. Several agents are either used "off label" or being studied as potential therapies for CS. Medications suppressing adrenal steroidogenesis currently in use include ketoconazole, metyrapone, mitotane, or etomidate. In addition, the investigational agent LCI699 is under study. Centrally acting agents, which suppress ACTH secretion, include cabergoline, octreotide, as well as the investigational agents pasireotide, bexarotene, and lapatinib, which are being studied in patients with pituitary tumors. Mifepristone, a type 2 glucocorticoid receptor antagonist, was recently approved by the FDA as a new therapy for CS. Although not definitive at present, medical therapies have an important role in the management of CS patients. It is anticipated that understanding the pathogenesis of these tumors at a molecular level may spawn the development of rationally designed, highly efficacious medical therapies for CS in the future.
 ...
PMID:Advances in medical therapies for Cushing's syndrome. 2236 76


<< Previous 1 2