Destabilization of actin filaments as a requirement for the secretion of catecholamines from permeabilized chromaffin cells.
In the search for a functional role of cytoskeletal proteins in the mechanism(s) of stimulus-secretion coupling, we have previously demonstrated that the actomyosin system might be involved in the transport of cations across the plasma membrane of bovine adrenal chromaffin cells [(1986) J. Biol. Chem. 261, 5745-5750]. To establish whether actin and myosin might also be involved in later stages of the cellular response, we have examined the possible effects of various actin-specific reagents on the calcium-mediated secretion of catecholamines from digitonin-permeabilized cells. F-Actin-destabilizing agents, such as cytochalasin D or DNase 1, were found to promote Ca2+-stimulated (as well as basal) secretion. By contrast, stabilizers, like phalloidin, produced the opposite effect. It is concluded that stimulus-secretion coupling in chromaffin cells might require the reorganization of actin for modulating both ion transport across the plasma membrane and exocytotic secretion per se.
D008841:Actin Cytoskeleton / Q000502:physiology* / Q000648:ultrastructure; D000199:Actins / Q000502:physiology*; D000313:Adrenal Medulla / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D002417:Cattle; D002463:Cell Membrane Permeability; D015638:Cytochalasin D; D003572:Cytochalasins / Q000494:pharmacology; D003599:Cytoskeleton / Q000502:physiology*; D003850:Deoxyribonuclease I / Q000494:pharmacology; D004072:Digitonin; D066298:In Vitro Techniques; D015879:Myosin Subfragments / Q000494:pharmacology; D010590:Phalloidine / Q000494:pharmacology; D012636:Secretory Rate / Q000187:drug effects
D000199:Actins; D002395:Catecholamines; D003572:Cytochalasins; D015879:Myosin Subfragments; D010590:Phalloidine; D015638:Cytochalasin D; D003850:Deoxyribonuclease I; D004072:Digitonin