Role of ATP and Na+ in the Regulation of Cytosolic Free Calcium in Kidney Cells
Part of the
Advances in Experimental Medicine and Biology
book series (AEMB, volume 232)
Cytosolic free calcium (Cai 2+) is controlled by several calcium transporters located at the plasma membrane, the inner membrane of the mitochondria and in the endoplasmic reticulum. Fig. 1 shows the various ATP-dependent pumps and antiporters involved in the control of Cai 2+ and Nai + (In this figure, the plasmalemmal Na+-Ca2+ antiporter is conventionally assumed to operate in the forward mode i.e. Ca2+ efflux energized by Na+ influx). Since Ca2+ transport out of the cell can be energized by ATP or by the Na+ electrochemical potential ΔμNa+, a fall in cellular ATP or a drop in ΔμNa+ would be expected to depress Ca2+ efflux, raise Cai 2+ and increase the cell Ca2+ content. In recent experiments (1,2) performed with cultured monkey kidney cells (LLC-MK2), my collaborators Dr. K.W. Snowdowne, C.C. Freudenrich and I found that only one of these three predictions was proved correct.
KeywordsKidney Cell Calcium Influx Biological Chemist Reverse Mode Cytosolic Free Calcium
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
K. W. Snowdowne, C. C. Freudenrich and A. B. Borle. The effects of anoxia on cytosolic free calcium, calcium fluxes and cellular ATP levels in cultured kidney cells. J. Biol. Chem. 260, 11619–11626, 1985PubMedGoogle Scholar
K. W. Snowdowne and A. B. Borle. Effects of low extracellular sodium on cytosolic ionized calcium. Na+
exchange as a major calcium influx pathway in kidney cells. J. Biol. Chem. 260, 14998–15007, 1985PubMedGoogle Scholar
A. B. Borle and K. W. Snowdowne. The measurement of intracellular ionized calcium with aequorin. Method. Enzymol. 124, 90–116, 1986CrossRefGoogle Scholar
J. Mason, F. Beck, A. Dorge, R. Rick and K. Thurau. Intracellular electrolyte composition following renal ischemia. Kidney Int. 20, 61–70, 1981PubMedCrossRefGoogle Scholar
M. Paulmichl, F. Friedrich and F. Lang. Electrical properties of Madin-Darby-canine-kidney cells. Effects of extracellular sodium and calcium. Pflügers Arch. 407, 258–263, 1986PubMedCrossRefGoogle Scholar
© Plenum Press, New York 1988