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Schlagwörter:
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Zusammenfassung:
Intracellular mechanisms involved in the regulation of cytosolic free Ca2+ concentration are very similar in different cell types including exocrine glandular and smooth muscle cells. Since altered calcium metabolism in vascular smooth muscle cells is one important factor involved in the pathogenesis of hypertension, understanding of regulation of cytosolic free Ca2+ concentration is necessary for effective treatment of this disease. In the following, main intracellular pathways in receptor-mediated stimulation of intracellular Ca2+ release, of Ca2+ influx into cells, and of Ca2+- dependent processes in stimulus-response coupling will be discussed. Furthermore, mechanisms involved in the regulation of stimulatory events that lead back to the resting state of the cell will be described. The cell types to be discussed are the acinar cell of the exocrine pancreas and the vascular smooth muscle cell. Although there are basic differences between both types of cells in that smooth muscle cells are excitable, whereas exocrine glandular cells are not, there are also striking similarities in receptor-mediated intracellular events. These pathways, termed “stimulus-secretion coupling” in exocrine glands and “pharmacomechanical coupling” in smooth muscle cells, will be compared in the following.
