Calcium receptor

Calcium receptor modulators High dose oestrogens... 

Calcium receptor Extracellular calcium-sensing receptor (CaSR)... 

Calcium receptors Membranes of vesicles. Many enzymes (kinases). 

Tamir, H., Liu, K. P., Adlersberg, M., Hsiung, S. C. and Gershon, M. D. Acidification of serotonin-containing secretory vesicles induced by a plasma membrane calcium receptor. J. Biol. Chem. 271 6441-6450,1996. 

Heath, H., Odelberg, S., Jackson, C. E., et al. (1996) Clustered inactivating mutations and benign polymorphisms of the calcium receptor gene in familial benign hypocalciuric hypercalcemia suggest receptor functional domains. J. Clin. Endocrinol. Metab. 81, 1312-1317. 

Mechanism of Action A calcium receptor agonist that increases the sensitivity of the calcium-sensing receptor on the parathyroid gland to extracellular calcium, thus low-eringthe parathyroid hormone (PTH) levels. TiierapeHtic Effect Decreases serum calcium and PTH levels. 

Pani L, Kuzmin A, Diana M, et al Calcium receptor antagonists modify cocaine effects in the central nervous system differently. Eur J Pharmacol 190 217-221, 1990... 

System 22 is an earlier example which incorporates Tsien s selective calcium receptor 23. ° System 23 has also been employed for the construction of ratiometric fluorescent sensors involving wavelength shifts. System 22 and other related PET sensors provide some of the most visually dramatic fluorescence off-on switching induced by biologically relevant levels of calcium ions in addition to their consistent predictability of most sensor parameters. 

Steddon SJ, Cunningham J Calcimimetics and calcilytics—fooling the calcium receptor. Lancet 2005 365 2237. [PMID 15978932]... 

Fuchs, F. Chemical properties of the calcium receptor site of troponin as determined from binding studies. In Calcium binding proteins (eds. W. Drabikowski, H. Strzelecka-Golaszewska and E. Carafoli), pp. 1-27. Amsterdam Elsevier Scientific Publ. and Warszawa PWN-Polish Scientific Publ. 1974. 

Carling, T, Szabo, E, Bai, M, Ridefelt, P, Westin, G, Gustavsson, P, Trivedi, S, Heilman, P, Brown, EM, Dahl, N and Rastad, J, 2000, Familial hypercalcemia and hypercalciuria caused by a novel mutation in the cytoplasmic tail of the calcium receptor, J Clin Endocrinol Metab 85 2042-2047... 

Fox, J, Fowe, SH, Petty, BA and Nemeth, EF, 1999, NPS R-568 a type II calcimimetic compound that acts on parathyroid cell calcium receptor of rats to reduce plasma levels of parathyroid hormone and... 

Garrett, JE, Capuano, IV, Hammerland, LG, Hung, BC, Brown, EM, Hebert, SC, Nemeth, EF and Fuller, F, 1995, Molecular cloning and functional expression of human parathyroid calcium receptor cDNAs, J Biol Chem 270 12919-12925... 

Gowen, M, Stroup, GB, Dodds, RA, James, IE, Votta, BJ, Smith, BR, Bhatnagar, PK, Lago, AM, Callahan, JF, DelMar, EG, Miller, MA, Nemeth, EF and Fox, J, 2000, Antagonizing the parathyroid calcium receptor stimulates parathyroid hormone secretion and bone formation in osteopenic rats, J Clin Invest 105 1595-1604... 

Nemeth, E and Scarpa, A, 1987, Rapid mobilization of cellular Ca2+ in bovine parathyroid cells by external divalent cations, J Biol Chem 202 5188-5196 Nemeth, EF, Fox, J, Delmar, EG, Steffey, ME, Lambert, LD, Conklin, RL, Bhatnagar, PK and Gowen, M, 1998a, Stimulation of parathyroid hormone secretion by a small molecule antagonist of the calcium receptor., J Bone Miner Res 23 S156 (absract 1030)... 

Nemeth, EF, Steffey, ME, Hammerland, LG, Hung, BC, Van Wagenen, BC, DelMar, EG and Balandrin, MF, 1998b, Calcimimetics with potent and selective activity on the parathyroid calcium receptor, Proc Natl Acad Sci U S A 95 4040-4045... 

Bax CM, Shankar VS, Moonga BS, Huang CL-H, Zaidi M. 1992. Is the osteoclast calcium receptor a receptor-operated calcium channel Biochem Biophys Res Communl83 619—625. 

Pazianas M, Zaidi M, Huang CL-H, Moonga BS, Shankar VS. 1993. Voltage-sensitivity of the osteoclast calcium receptor. Biochem Biophys Res Communl92 1100-5. 

Zaidi M. 1990. Calcium receptors on eukaryotic cells with special reference to the osteoclast. Biosci Rep 10 493-507. 

Zaidi M, Kerby J, Huang C.-H, Alam ASMT, Rathod H, Chambers TJ, Moonga BS. 1991. Divalent cations mimic the inhibitory effects of extracellular ionized calcium on bone resorption by isolated rat osteoclasts Further evidence for a calcium receptor . J Cell Physiol 149 422-7. 

Another new strategy involves drugs that stimulate calcium receptors on the parathyroid gland, thereby inhibiting the release of PTH.49 As indicated... 

This rather common disease, if associated with symptoms and significant hypercalcemia, is best treated surgically. Oral phosphate and bisphosphonates have been tried but cannot be recommended. Asymptomatic patients with mild disease in general do not get worse and may be left untreated. The calcimimetic agents, a new class of drugs that act through the calcium receptor, are in clinical trials. If they prove efficacious, medical management of this disease will need to be reconsidered. 

G-protein results in a decrease of intracellular calcium. Receptors that are able to activate PLC (phospholipase C) enzymes cause release of Ca2+ from intracellular stores and influence Ca2+ entry across the plasma membrane (Werry et al. 2003). 

Both intracellular release and transmembrane flux contribute to the rise in intracellular Ca2+.14,15 The rise in keratinocyte intracellular Ca2+ in response to raised extracellular Ca2+ has two phases (a) an initial peak, not dependent on extracellular Ca2+ and (b) a later phase that requires extracellular Ca2+.14 An early response of human keratinocytes to increases in extracellular Ca2+ is an acute increase in intracellular Ca2+. Stepwise addition of extracellular Ca2+ to neonatal human keratinocytes is followed by a progressive increase in intracellular Ca2+, where the initial spike of increased intracellular Ca2+ is followed by a prolonged plateau of higher intracellular Ca2+.16 The response of intracellular Ca2+ to increased extracellular Ca2+ in keratinocytes is saturated at 2.0 mM extracellular Ca2+.16,17 The response of intracellular Ca2+ to increased extracellular Ca2+ in keratinocytes resembles the response in parathyroid cells, in that a rapid and transient increase in intracellular Ca2+ is followed by a sustained increase in intracellular Ca2+ above basal level. This multiphasic response is attributed to an initial release of Ca2+ from intracellular stores followed by an increased influx of Ca2+ through voltage-independent cation channels. The keratinocyte and parathyroid cell contains a similar cell membrane calcium receptor thought to mediate this response to extracellular Ca2+. This receptor can activate the phospholipase-C pathway, leading to an increase... 

Voltage-dependent L-type calcium receptors have four distinct binding sites near the pore for calcium flux. By binding to these receptor sites calcium channel antagonists block the inward calcium current through the L-type channels and antagonize increases in heart rate, SA/AV node conduction, and heart contraction. Calcium... 

It was not until 1969 that the first calcium receptor protein, troponin-C was isolated from muscle by Ebashi [14], Shortly afterward, another calcium receptor, calmodulin [15] was identified and it became apparent that unlike the cAMP messenger system, more than one receptor protein existed for calcium. 

A calcium regulated enzyme or protein could be considered as the third type of calcium binding protein. The calcium regulated enzyme is contrasted to the target protein of the calcium dependent regulatory protein in that the calcium regulated enzymes are capable of binding calcium directly and do not require additional proteins to confer calcium sensitivity. An example of this type of calcium receptor is the protein kinase C [8]. 

How would a mutation that inactivates the parathyroid calcium receptor (CaR) affect calcium homeostasis ... 

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