title: K+-induced swelling of the dogfish shark (Squalus acanthias) rectal gland cells is associated with changes of the cytoskeleton.
abstract: Dogfish shark (Squalus acanthias) rectal gland cells swell massively when incubated in elasmobranch media in which Na+ was equivalently replaced by K+; this swelling was abolished when the impermeant gluconate replaced Cl-, while the cell depolarization was comparable in both media. The K+-effect was associated with (a) an increase of the steady-state 42K (and 86Rb) efflux (particularly of the rate constant of the fast cellular efflux component) and a rearrangement of the respective cellular pools of K+; (b) an alteration of cell morphology and the pattern of the F-actin staining along the basolateral cell membrane as revealed with fluorescent analogs of phallacidin. These changes were independent of cell volume, being identical in KCl and K-gluconate media. The observations were specific for K+ (and Rb+): replacement of media Na+ by Li+ (which is not actively extruded by the cells), or the presence of ouabain, produced only minor swelling without affecting cell morphology and F-acting distribution. The results are consistent with the following view: as opposed to Na+ or Li+ media, the K+-induced changes of the cortical F-actin component of the cytoskeleton permit the observed massive cell swelling due to the osmotic contribution of intracellular impermeant anion(s).
authors: Department of Physiology, University of Pennsylvania, Philadelphia 19104-6085.
authors: A
authors: A
authors: Kleinzeller
authors: J W
authors: JW
authors: Mills
mesh_terms: D000199:Actins / Q000502:physiology; D000818:Animals; D000838:Anions / Q000494:pharmacology; D002414:Cations, Monovalent / Q000378:metabolism / Q000494:pharmacology; D003599:Cytoskeleton / Q000502:physiology*; D004284:Dogfish / Q000033:anatomy & histology / Q000502:physiology*; D066298:In Vitro Techniques; D008094:Lithium / Q000378:metabolism; D008854:Microscopy, Electron; D011188:Potassium / Q000494:pharmacology*; D012413:Rubidium / Q000378:metabolism; D012491:Salt Gland / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D012754:Sharks / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000187:drug effects*
chemical_list: D000199:Actins; D000838:Anions; D002414:Cations, Monovalent; D008094:Lithium; D012413:Rubidium; D011188:Potassium