Calcium cellular proliferation

The CaR regulates numerous biological processes, including the expression of various genes (e.g., PTH) the secretion of hormones (PTH and calcitonin), cytokines (MCP-1), and calcium (e.g., into breast milk) the activities of channels (potassium channels) and transporters (aquaporin-2) cellular shape, motility (of macrophages), and migration cellular adhesion (of hematopoietic stem cells) and cellular proliferation (of colonocytes), differentiation (of keratinocytes), and apoptosis (of H-500 ley dig cancer cells) [3]. 

In addition to the organs responsible for the development and maintenance of the fetus and newborn, l,25(OH)2D3 receptors have also been localized in several organs from the reproductive apparatus such as the uterus [71], ovary [72] and testis [73]. Since these tissues are not directly associated with calcium translocations, the presence of l,25(OH)2D3 receptors may be related to a role of the hormone in cellular proliferation, differentiation and/or maturation. Accordingly, the levels of testicular l,25(OH)2D3 receptors have been found to correlate with the meiotic and mitotic development of the spermatogonia [73], Clearly, more studies are needed in this area to clarify the role of the vitamin D hormone in these tissues. However,... 

Buckley NE, Su Y, Milstein S, et al. (1995) The role of calcium influx in cellular proliferation induced by interaction of endogenous ganglioside Gmi with the B subunit of cholera toxin. In Biochim. Biophys. Acta 1256 275—283. 

Barsoum GH, Thompson J, Neoptolemos JP, et al. 1992. Dietary calcium does not reduce experimental colorectal carcinogenesis after small bowel resection despite reducing cellular proliferation. Gut 33 1515-1520. 

Extracellular calcium and regulation of cellular proliferation and differentiation. 

The transcription factor NP-kB controls the expression of numerous genes that modulate the immune and stress responses, onset, and the resolution of inflammation, cell adhesion, calcium homeostasis, maintenance of intercellular communications, and regulation of cellular proliferation, and protection against... 

Disease States. Rickets is the most common disease associated with vitamin D deficiency. Many other disease states have been shown to be related to vitamin D. These can iavolve a lack of the vitamin, deficient synthesis of the metaboUtes from the vitamin, deficient control mechanisms, or defective organ receptors. The control of calcium and phosphoms is essential ia the maintenance of normal cellular biochemistry, eg, muscle contraction, nerve conduction, and enzyme function. The vitamin D metaboUtes also have a function ia cell proliferation. They iateract with other factors and receptors to regulate gene transcription. 

The effect of sphingosine on other enzymes may also contribute to its apoptotic effect. These include the inhibition of calcium/calmodulin-requiring enzymes and DNA primase and the stimulation of casein kinase II and several unidentified kinases (Alessenko, 2000). In addition, sphingosine can increase the cellular concentration of cyclic AMP, which is inhibitory for proliferation in many cell types (Pyne and Pyne, 1996). 

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