PMID- 10390518
OWN - NLM
STAT- MEDLINE
DCOM- 19990723
LR  - 20220309
IS  - 0031-9333 (Print)
IS  - 0031-9333 (Linking)
VI  - 79
IP  - 3
DP  - 1999 Jul
TI  - Sodium/calcium exchange: its physiological implications.
PG  - 763-854
AB  - The Na+/Ca2+ exchanger, an ion transport protein, is expressed in the plasma
      membrane (PM) of virtually all animal cells. It extrudes Ca2+ in parallel with
      the PM ATP-driven Ca2+ pump. As a reversible transporter, it also mediates Ca2+
      entry in parallel with various ion channels. The energy for net Ca2+ transport by
      the Na+/Ca2+ exchanger and its direction depend on the Na+, Ca2+, and K+
      gradients across the PM, the membrane potential, and the transport stoichiometry.
      In most cells, three Na+ are exchanged for one Ca2+. In vertebrate
      photoreceptors, some neurons, and certain other cells, K+ is transported in the
      same direction as Ca2+, with a coupling ratio of four Na+ to one Ca2+ plus one
      K+. The exchanger kinetics are affected by nontransported Ca2+, Na+, protons,
      ATP, and diverse other modulators. Five genes that code for the exchangers have
      been identified in mammals: three in the Na+/Ca2+ exchanger family (NCX1, NCX2,
      and NCX3) and two in the Na+/Ca2+ plus K+ family (NCKX1 and NCKX2). Genes
      homologous to NCX1 have been identified in frog, squid, lobster, and Drosophila. 
      In mammals, alternatively spliced variants of NCX1 have been identified; dominant
      expression of these variants is cell type specific, which suggests that the
      variations are involved in targeting and/or functional differences. In cardiac
      myocytes, and probably other cell types, the exchanger serves a housekeeping role
      by maintaining a low intracellular Ca2+ concentration; its possible role in
      cardiac excitation-contraction coupling is controversial. Cellular increases in
      Na+ concentration lead to increases in Ca2+ concentration mediated by the
      Na+/Ca2+ exchanger; this is important in the therapeutic action of cardiotonic
      steroids like digitalis. Similarly, alterations of Na+ and Ca2+ apparently
      modulate basolateral K+ conductance in some epithelia, signaling in some special 
      sense organs (e.g., photoreceptors and olfactory receptors) and Ca2+-dependent
      secretion in neurons and in many secretory cells. The juxtaposition of PM and
      sarco(endo)plasmic reticulum membranes may permit the PM Na+/Ca2+ exchanger to
      regulate sarco(endo)plasmic reticulum Ca2+ stores and influence cellular Ca2+
      signaling.
FAU - Blaustein, M P
AU  - Blaustein MP
AD  - Departments of Physiology, University of Maryland School of Medicine, Baltimore, 
      USA.
FAU - Lederer, W J
AU  - Lederer WJ
LA  - eng
GR  - HL-25675/HL/NHLBI NIH HHS/United States
GR  - HL-45215/HL/NHLBI NIH HHS/United States
GR  - NS-16106/NS/NINDS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PT  - Review
PL  - United States
TA  - Physiol Rev
JT  - Physiological reviews
JID - 0231714
RN  - 0 (Sodium-Calcium Exchanger)
SB  - IM
MH  - Amino Acid Sequence/genetics
MH  - Animals
MH  - Base Sequence/genetics
MH  - Humans
MH  - Kinetics
MH  - Molecular Sequence Data
MH  - Sodium-Calcium Exchanger/genetics/*physiology
MH  - Structure-Activity Relationship
RF  - 1010
EDAT- 1999/07/03 00:00
MHDA- 1999/07/03 00:01
CRDT- 1999/07/03 00:00
PHST- 1999/07/03 00:00 [pubmed]
PHST- 1999/07/03 00:01 [medline]
PHST- 1999/07/03 00:00 [entrez]
AID - 10.1152/physrev.1999.79.3.763 [doi]
PST - ppublish
SO  - Physiol Rev. 1999 Jul;79(3):763-854. doi: 10.1152/physrev.1999.79.3.763.