Calcium cellular transport processes

JR Williamson, SK Joseph, KE Coll, AP Thomas, A Verhoeven, M Prentki. (1986). Hormone-induced inositol lipid breakdown and calcium-mediated cellular responses in liver. In G Poste, ST Crooke, eds. New Insights into Cell and Membrane Transport Processes. New York Plenum Press, pp 217-247. 

Flik, G., Verbost, P. M. and Wendelaar Bonga, S. E. (1995). Calcium transport processes in fish. In Cellular and Molecular Approaches to Fish Ionic Regulation. eds. Wood, C. M. and Shuttleworth, T. J., Fish Physiology Series, Vol. 14, Academic Press, San Diego, pp. 317-342. 

As mentioned above, palytoxin produces multiple pharmacological actions at the cellular, tissue, and organism level. Alterations in the Na" and gradients by the toxin will initiate a complex chain of cellular events it could alter the active transport of various ions as well as the transport processes across intracellular membranes. One important parameter that can be altered by palytoxin is the cytosolic free calcium concentration, which will produce alterations in numerous cellular processes. 

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]. 

There is reason to beheve that cardiac glycosides, like other inotropic substances, act on the contractibility of the heart by affecting the process of calcium ion transfer through the membrane of myocardiocytes. The effect of cellular membranes in electric conductivity is mediated by transport of sodium, calcium, and potassium ions, which is a result of indirect inhibitor action on the (Na+-K+) ATPase of cell membranes. 

Molecular and cellular organization of transepithelial calcium transport Calcium transport across the intestinal and renal epithelium proceeds on a transcellular as well as on a paracellular route. Transfer across polarized cells is a vectorial multi-step process (Bronner 1990, 1991), which encompasses (i) calcium entry across the brush-border membrane via two types of calcium channels (Muller et al. 2000, Peng etal. 2000, Slepchenko and Bronner 2001) ... 

Phosphorus has more known functions in the animal body than any other mineral element. Together with calcium, phosphorus plays a major role in the formation of bones and teeth, as well as eggshells. It is a component of nucleic acids, which control cell multiplication, growth and differentiation. In combination with other elements, phosphorus has a role in the maintenance of cellular osmotic pressure and the acid-base balance. Energy transfer processes in all living cells involve interconversion of the phosphate-containing nucleotides, adenosine diphosphate (ADP) and ATP, and thus phosphorus participates in all biological events. Other roles include its presence in phospholipids, where it functions in cell-wall structure, fatty acid transport and protein as well as amino acid formation. 

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