Duck erythrocytes were incubated in hypotonic media at tonicities which do not produce hemolysis. The cells' response can be divided into two phases: an initial rapid phase of osmotic swelling and a second more prolonged phase (volume regulatory phase) in which the cells shrink until they approach their initial isotonic volume. Shrinkage associated with the volume regulatory phase is the consequence of a nearly isosmotic loss of KCl and water from the cell. The potassium loss results from a transient increase in K efflux. There is also a small reduction in Na permeability. Changes in cell size during the volume regulatory phase are not altered by 10-4 M ouabain although this concentration of ouabain does change the cellular cation content. The over-all response of duck erythrocytes is considered as an example of "isosmotic intracellular regulation," a term used to describe a form of volume regulation common to euryhaline invertebrates which is achieved by adjusting the number of effective intracellular osmotic particles. The volume regulatory phase is discussed as the product of a membrane mechanism which is sensitive to some parameter associated with cell volume and is capable of regulating the loss of potassium from the cell. This mechanism is able to regulate cell size when the Na-K exchange, ouabain-inhibitable pump mechanism is blocked.
Article|
October 01 1971
The Response of Duck Erythrocytes to Nonhemolytic Hypotonic Media : Evidence for a volume-controlling mechanism
Floyd M. Kregenow
Floyd M. Kregenow
From the Laboratory of Kidney and Electrolyte Metabolism, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland 20014
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Floyd M. Kregenow
From the Laboratory of Kidney and Electrolyte Metabolism, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland 20014
Received:
January 18 1971
Online Issn: 1540-7748
Print Issn: 0022-1295
Copyright © 1971 by The Rockefeller University Press
1971
J Gen Physiol (1971) 58 (4): 372–395.
Article history
Received:
January 18 1971
Citation
Floyd M. Kregenow; The Response of Duck Erythrocytes to Nonhemolytic Hypotonic Media : Evidence for a volume-controlling mechanism . J Gen Physiol 1 October 1971; 58 (4): 372–395. doi: https://doi.org/10.1085/jgp.58.4.372
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