Rat liver slices incubated at 1°C in phosphate (10 mM) or bicarbonate (25 mM) plus phosphate (2 mM)—buffered Ringer's solutions containing 1.2 mM Ca2+ underwent a 3-fold increase in Ca2+ content relative to their fat-free solids, and lost 10% of their Mg2+. Upon subsequent incubation at 38°C, slices in the bicarbonate medium lost about half of the accumulated Ca2+. This extrusion was less efficient in the phosphate medium. Succinate (40 mM), which strongly stimulated respiration, caused an accumulation of Ca2+ in slices incubated in the phosphate medium. The extrusion of Ca2+ was prevented by respiratory inhibitors, but not by inhibition of the Na+ and K+ transport (by ouabain or K+-free medium). This suggests that the Ca2+ transport was itself directly dependent on high-energy compounds and was not due to a hetero-exchange diffusion of Ca2+ against Na+ ions. Some evidence was obtained for the occurrence of an active accumulation of Mg+ ions.
Article| January 01 1970
Net Movements of Calcium and Magnesium in Slices of Rat Liver
G. D. V. van Rossum
From the Johnson Research Foundation, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104.
Dr. van Rossum's present address is Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Received: July 01 1969
Online Issn: 1540-7748
Print Issn: 0022-1295
Copyright © 1970 by The Rockefeller University Press
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G. D. V. van Rossum; Net Movements of Calcium and Magnesium in Slices of Rat Liver . J Gen Physiol 1 January 1970; 55 (1): 18–32. doi: https://doi.org/10.1085/jgp.55.1.18
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