Receptor epidermal growth hormone

Considerable cross-talk also occurs between different hormones at the level of receptor function. For instance, the diacylglycerol-activated protein kinase C phosphory-lates and thereby inhibits the activity of insulin and epidermal growth factor receptor kinases (epidermal growth factor is discussed in a later section). Likewise, when cAMP-dependent protein kinases are active they can inhibit receptors for epinephrine by phosphorylating them. 

Human growth hormone (GHl, Fig. 1), epidermal growth factor (EGF), insnlin (INS), platelet-derived growth factor (PDGF), and many cytokines bind receptors that activate intracellular tyrosine kinase activity. The major isoform of GHl is a protein of 191 amino acids (22 KDa) that fnnctions in part to stimulate the growth of bone and internal organs in children. As shown in Fig. 1, the human growth hormone receptor (GHR), which is a member of the cytokine-hematopoietin receptor superfamily. 

Model I has been applied to a wide variety of drug responses, such as the reduction of fever (8, 20) or pain (19) by anti-inflammatory drugs, anticoagulant action of warfarin (3,9), reduction in blood sorbitol levels by inhibitors of aldose reductase (21), cortisol suppressive effects of corticosteroids (22), luteinizing hormone suppression by the synthetic hormone cetrorelix (23), reduction in the levels of tumoral phospho-EGFR (epidermal growth factor receptor) by cetuximab (24), inhibition of dihydrotestosterone (25), the suppression of T-lymphocyte influx into the blood by corticosteroids (26), and the acid-inhibitory effects of H2-receptor antagonists (27). 

Carrasco, E., Blum, M., Weickert, C. S., and Casper, D. (2003). Epidermal growth factor receptor expression is related to post-mitotic events in cerebellar development Regulation by thyroid hormone. Brain Res. Dev. Brain Res. 140, 1-13. 

Receptor HCG Human chorionogonadotropic hormone HER2 Human Epidermal Growth Factor Receptor-2 ICAM-1 Intracellular adhesion molecule-1 LAGS ... 

Whereas epidermal growth factor (EGF) enhances the radiosensitivity of human squamous ceU carcinoma cells in vitro (197), addition of EGF to hormone-deprived MCE-7 breast cancer cells prior to irradiation results ia iacreased radioresistance (198). An anti-EGE-receptor monoclonal antibody blocks the abiUty of EGE to enhance growth and radioresistance. Tumor cells, the growth of which is stimulated by EGE, appear to be protected those where growth is iohibited are sensitized (198). 

III. Tyr protein kinases A. Cytosolic tyrosine kinases src, fgr, abl, etc.) B. Receptor tyrosine kinases (RTKs) Plasma membrane receptors for hormones such as epidermal growth factor (EGF) or platelet-derived growth factor (PDGE) Raf (a protein kinase)... 

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