PMID- 14684869
OWN - NLM
STAT- MEDLINE
DCOM- 20040116
LR  - 20200225
IS  - 1529-2401 (Electronic)
IS  - 0270-6474 (Print)
IS  - 0270-6474 (Linking)
VI  - 23
IP  - 37
DP  - 2003 Dec 17
TI  - Distribution of K+-dependent Na+/Ca2+ exchangers in the rat supraoptic 
      magnocellular neuron is polarized to axon terminals.
PG  - 11673-80
AB  - Neurons are polarized into compartments such as the soma, dendrites, and axon 
      terminals, each of which has highly specialized functions. To test whether Ca2+ 
      is differently handled in different compartments of a neuron, we investigated 
      Ca2+ clearance mechanisms in somata of supraoptic magnocellular neurosecretory 
      cells (MNCs) and in their axon terminals located in neurohypophyses. Using 
      patch-clamp and microfluorometry techniques, Ca2+ transients were evoked by 
      depolarizing pulses. Endogenous Ca2+ binding ratios (kappaS) and Ca2+ clearance 
      rates were calculated from the decay phases of Ca2+ transients according to the 
      single compartment model. Mean values of kappaS were 79 +/- 2.6 in somata of MNCs 
      and 187 +/- 19 in axon terminals. Ca2+ clearance rate in axon terminals, which 
      were calculated from time derivative of Ca2+ decay and the kappaS values, were 
      approximately threefold higher than in somata. In response to external Na+ 
      reduction, Ca2+ clearance rates were reduced by 65% in axon terminals, but did 
      not change in somata. Immunohistochemical assays confirmed that K+-dependent 
      Na+/Ca2+ exchanger (NCKX2) was specifically localized to neurohypophysial axon 
      terminals and was not found in somata. In somata, inhibition of sarcoendoplasmic 
      reticulum Ca2+-ATPase (SERCA) pumps, mitochondrial Ca2+-uniporter, and plasma 
      membrane Ca2+-ATPase (PMCA) pumps decreased Ca2+ clearance rate by 48, 27, and 
      21%, respectively. These results suggest that neurohypophysial axon terminals 
      have greater Ca2+ clearance power than somata because of the specific 
      localization of NCKX2, and that Ca2+ clearance in somata of MNCs is mediated by 
      SERCA pumps, mitochondrial uniporter, and PMCA pumps.
FAU - Kim, Myoung-Hwan
AU  - Kim MH
AD  - Department of Physiology, Seoul National University College of Medicine, 
      Chongno-Ku, Seoul, 110-799, Korea.
FAU - Lee, Sang-Hyuk
AU  - Lee SH
FAU - Park, Kyeong Han
AU  - Park KH
FAU - Ho, Won-Kyung
AU  - Ho WK
FAU - Lee, Suk-Ho
AU  - Lee SH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Neurosci
JT  - The Journal of neuroscience : the official journal of the Society for 
      Neuroscience
JID - 8102140
RN  - 0 (Sodium-Calcium Exchanger)
RN  - 147478-17-9 (potassium-dependent sodium-calcium exchanger)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Calcium/metabolism
MH  - Cell Polarity
MH  - Cells, Cultured
MH  - Ion Transport
MH  - Male
MH  - Neurons/*chemistry/metabolism
MH  - Patch-Clamp Techniques
MH  - Pituitary Gland, Posterior/cytology
MH  - Presynaptic Terminals/*chemistry/metabolism
MH  - Rats
MH  - Rats, Sprague-Dawley
MH  - Sodium-Calcium Exchanger/*analysis/physiology
MH  - Supraoptic Nucleus/*chemistry/cytology
PMC - PMC6740958
EDAT- 2003/12/20 05:00
MHDA- 2004/01/17 05:00
PMCR- 2004/06/17
CRDT- 2003/12/20 05:00
PHST- 2003/12/20 05:00 [pubmed]
PHST- 2004/01/17 05:00 [medline]
PHST- 2003/12/20 05:00 [entrez]
PHST- 2004/06/17 00:00 [pmc-release]
AID - 23/37/11673 [pii]
AID - 10.1523/JNEUROSCI.23-37-11673.2003 [doi]
PST - ppublish
SO  - J Neurosci. 2003 Dec 17;23(37):11673-80. doi: 10.1523/JNEUROSCI.23-37-11673.2003.