Calcium dependent process

Neher, E. and Zucker, R. S. Multiple calcium-dependent processes related to secretion in bovine chromaffin cells. Neuron 10 21-30,1993. 

There is considerable evidence that the release of 5-HT occurs by exocytosis, i.e. by the discharge from the cell of the entire content of individual storage vesicles. First, 5-HT is sufficiently ionized at physiological pH so that it does not cross plasma membranes by simple diffusion. Second, most intraneuronal 5-HT is contained in storage vesicles and other contents of the vesicle including SPB are released together with serotonin. By contrast, cytosolic proteins do not accompany electrical stimulation-elicited release of 5-HT. Third, the depolarization-induced release of 5-HT occurs by a calcium-dependent process indeed, it appears that the influx of extracellular calcium ions with or without membrane depolarization can increase the release of 5-HT. Calcium stimulates the fusion of vesicular membranes with the plasma membrane (see Chs 9,10). 

It should be released from the nerve terminal, generally by a calcium-dependent process, following stimulation of the nerve. 

Mariol, M.C., and Segalat, L., 2001, Muscular degeneration in the absence of dystrophin is a calcium-dependent process, Curr Biol, 11, pp 1691-1694. 

P/Q-type channels undergo a second calcium-dependent process whereby current activity increases following a strong membrane depolarization or a train of action potentials. This increase is only observed in the presence of external calcium, is insensitive to calcium buffers, and requires the high-affinity calcium binding sites on calmodulin (Chaudhuri et al. 2004 DeMaria et al. 2001). This process, termed calcium-dependent facilitation (CDF), is not observed with N-type or R-type channels and is Cav2.1 channel splice isoform dependent (Chaudhuri et al. 2004). The... 

Calcium-dependent processes relevant to pharmacological intervention mainly include pace-making in the heart, and contraction in heart and smooth muscle. These are affected by dmgs that either act on calcium channels directly, or on other receptors that will have some downstream effect on the cytosolic availability of calcium. Exemples are the p-and ttj-adrenergic receptors (see below). 

The chemistry of aluminium combines features in common with two other groups of elements, namely (i) divalent magnesium and calcium and (ii) trivalent chromium and iron. The toxic effects of aluminium are more related to its interference with calcium-dependent processes, whereas its access to tissues is probably a function of... 

The histamine release in the brain, and perhaps other sites, involves exocytosis, as this potassium-induced release is a calcium-dependent process. Histamine is released by many factors. For example, histamine is released by numer-ons drugs including reserpine, codeine, meperidine, hydralazine, morphine, d-tnbocurarine, dextrans, papaverine, and compound 48/80. However, the different histamine storage sites show certain degrees of specificity. For example, the histamine in mast cells is not released following potassium-induced depolarization or by reserpine, factors that release histamine from nenrons. Conversely, compound 48/80, which releases histamine from mast cells, is not able to release histamine from nenrons. 

Excitation-secretion coupling is a highly calcium-dependent process, and thus the calcium dependency of evoked release could be... 

Inorganic lead is an effective substitute for calcium (Ca) and influences calcium-dependent processes (1) Ca channels in the membrane of bovine medullary cells (2) Ca pump and Ca-ATPase in human RBCs (3) Ca uptake in mitochondria (4) calmodulin-dependent processes (5) binding to intestinal Ca-binding protein (6) Ca-dependent potassium permeability in human erythrocytes [41]. 

Calmodulin is a major intracellular calcium-binding protein which regulates a wide variety of calcium-dependent processes (Cheung 1982). The binding of calcium to calmodulin induces a conformational change in the protein to an active form. The calcium-calmodulin complex is then capable of regulating a host of other molecules such as phosphodiesterase, adenylate kinase, protein kinases, and Ca-ATPase. Cadmium has been shown to... 

Strontium is the most effective element in substituting for calcium in calcium-dependent processes in biological systems.Strontium can induce the conformational changes in calmodulin necessary for stimulation of bovine cyclic nucleotide phosphodiesterase and binding to the calmodulin antagonist trifluoperizine. 

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