PMID- 15649442
OWN - NLM
STAT- MEDLINE
DCOM- 20050707
LR  - 20131121
IS  - 0006-8993 (Print)
IS  - 0006-8993 (Linking)
VI  - 1031
IP  - 2
DP  - 2005 Jan 21
TI  - Transient increases in extracellular K+ produce two pharmacological distinct 
      cytosolic Ca2+ transients.
PG  - 174-84
AB  - Transient increases in extracellular K+ are observed under various conditions, 
      including repetitive neuronal firing, anoxia, ischemia and hypoglycemic coma. We 
      studied changes in cytoplasmic Ca2+ ([Ca2+]cyt) evoked by pulses of KCl in human 
      neuroblastoma SH-SY5Y cells and rat dorsal root ganglia (DRG) neurons at 37 
      degrees C. A "pulse" of KCl evoked two transient increases in [Ca2+]cyt, one upon 
      addition of KCl (K+on) and the other upon removal of KCl (K+off). The K+on 
      transient has been described in many cell types and is initiated by the 
      activation of voltage-dependent Ca2+ channels followed by Ca2+-evoked Ca2+ 
      release from intracellular Ca2+ stores. The level of KCl necessary to evoke the 
      K+off transient depends on the type of neuron, in SH-SY5Y cells it required 100 
      mM KCl, in most (but not all) of dorsal root ganglia neurons it could be detected 
      with 100-200 mM KCl and in a very few dorsal root ganglia neurons it was 
      detectable at 20-50 mM KCl. In SH-SY5Y cells, reduction of extracellular Ca2+ 
      inhibited the K+on more strongly than the K+off and slowed the decay of K+off. 
      Isoflurane (1 mM) reduced the K+on)- but not the K+off-peak. However, isoflurane 
      slowed the decay of K+off. The nonspecific cationic channel blocker La3+ (100 
      microM) had an effect similar to that of isoflurane. Treatment with thapsigargin 
      (TG) at a concentration known to only deplete IP3-sensitive Ca2+ stores did not 
      affect K+on or K+off, suggesting that Ca2+ release from the IP3-sensitive Ca2+ 
      stores does not contribute to K+on and K+off transients and that the 
      thapsigargin-sensitive Ca2+ ATPases do not contribute significantly to the rise 
      or decay rates of these transients. These findings indicate that a pulse of 
      extracellular K+ produces two distinct transient increases in [Ca2+]cyt.
FAU - Corrales, Alexandra
AU  - Corrales A
AD  - Anesthesiology Department, New York University School of Medicine, 550 First 
      Avenue, RR605, New York, NY 10016, USA.
FAU - Montoya G, Jose V
AU  - Montoya G JV
FAU - Sutachan, Jhon-Jairo
AU  - Sutachan JJ
FAU - Cornillez-Ty, Genoveve
AU  - Cornillez-Ty G
FAU - Garavito-Aguilar, Zayra
AU  - Garavito-Aguilar Z
FAU - Xu, Fang
AU  - Xu F
FAU - Blanck, Thomas J J
AU  - Blanck TJ
FAU - Recio-Pinto, Esperanza
AU  - Recio-Pinto E
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PL  - Netherlands
TA  - Brain Res
JT  - Brain research
JID - 0045503
RN  - 0 (Calcium Channels)
RN  - RWP5GA015D (Potassium)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Animals
MH  - Calcium/*metabolism
MH  - Calcium Channels/metabolism
MH  - Calcium Signaling/*physiology
MH  - Cytosol/*metabolism
MH  - Extracellular Fluid/chemistry
MH  - Ganglia, Spinal/cytology
MH  - Humans
MH  - Membrane Potentials/physiology
MH  - Neuroblastoma
MH  - Neurons/cytology/*metabolism
MH  - Potassium/analysis/*metabolism
MH  - Rats
MH  - Signal Transduction/*physiology
MH  - Tumor Cells, Cultured
EDAT- 2005/01/15 09:00
MHDA- 2005/07/08 09:00
CRDT- 2005/01/15 09:00
PHST- 2004/10/28 00:00 [accepted]
PHST- 2005/01/15 09:00 [pubmed]
PHST- 2005/07/08 09:00 [medline]
PHST- 2005/01/15 09:00 [entrez]
AID - S0006-8993(04)01758-5 [pii]
AID - 10.1016/j.brainres.2004.10.031 [doi]
PST - ppublish
SO  - Brain Res. 2005 Jan 21;1031(2):174-84. doi: 10.1016/j.brainres.2004.10.031.