ATP-stimulated Ca2+-activated K+ efflux pathway and differentiation of human placental cytotrophoblast cells

L. H. Clarson, Victoria Roberts, S. L. Greenwood, A. C. Elliott

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The aim of this study was to determine whether extracellular ATP ([ATP]o) stimulated a Ca2+-activated K+ efflux in trophoblast cells that was dependent on extracellular Ca2+ ([Ca2+]o). Cytotrophoblast cells, isolated from human placenta, were examined following 18 h (relatively undifferentiated) and 66 h (multinucleate cells) of culture. Potassium efflux was measured using 86Rb as a trace marker. Intracellular Ca2+ ([Ca2+]i) was examined by microfluorometry using fura 2. [ATP]o significantly increased 86Rb efflux to a peak that declined to control (18-h cells) or an elevated plateau (66-h cells) and was inhibited by 100 nM charybdotoxin. Removing [Ca2+]o significantly reduced 86Rb efflux in both groups as did application of 150 μM GdCl3. [ATP]o significantly increased [Ca2+]i in both groups of cells. The response was reduced by removing [Ca2+]o and applying 150 μM GdCl3. For both 86Rb efflux and microfluorometry experiments, the response to [ATP]o was more dependent on [Ca2+]o in 66-h cells compared with 18-h cells (∼70% greater). Cytotrophoblast cells exhibit an [ATP]o-stimulated Ca2+-activated K+ efflux. The dependency of this pathway on [Ca2+]o is greater in the 66-h multinucleate syncytiotrophoblast-like cells, suggesting that the mechanism for Ca2+ entry may be altered during differentiation of trophoblast cells.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume282
Issue number4 51-4
StatePublished - 2002
Externally publishedYes

Fingerprint

Trophoblasts
Adenosine Triphosphate
Cytophotometry
Charybdotoxin
Fura-2
Placenta
Cell Differentiation
Potassium
Cell Culture Techniques

Keywords

  • Calcium entry
  • Human placenta
  • Intermediate calcium-activated potassium channel

ASJC Scopus subject areas

  • Physiology

Cite this

ATP-stimulated Ca2+-activated K+ efflux pathway and differentiation of human placental cytotrophoblast cells. / Clarson, L. H.; Roberts, Victoria; Greenwood, S. L.; Elliott, A. C.

In: American Journal of Physiology - Regulatory Integrative and Comparative Physiology, Vol. 282, No. 4 51-4, 2002.

Research output: Contribution to journalArticle

@article{29813fdc7eb745f6b4f5b22f228ba984,
title = "ATP-stimulated Ca2+-activated K+ efflux pathway and differentiation of human placental cytotrophoblast cells",
abstract = "The aim of this study was to determine whether extracellular ATP ([ATP]o) stimulated a Ca2+-activated K+ efflux in trophoblast cells that was dependent on extracellular Ca2+ ([Ca2+]o). Cytotrophoblast cells, isolated from human placenta, were examined following 18 h (relatively undifferentiated) and 66 h (multinucleate cells) of culture. Potassium efflux was measured using 86Rb as a trace marker. Intracellular Ca2+ ([Ca2+]i) was examined by microfluorometry using fura 2. [ATP]o significantly increased 86Rb efflux to a peak that declined to control (18-h cells) or an elevated plateau (66-h cells) and was inhibited by 100 nM charybdotoxin. Removing [Ca2+]o significantly reduced 86Rb efflux in both groups as did application of 150 μM GdCl3. [ATP]o significantly increased [Ca2+]i in both groups of cells. The response was reduced by removing [Ca2+]o and applying 150 μM GdCl3. For both 86Rb efflux and microfluorometry experiments, the response to [ATP]o was more dependent on [Ca2+]o in 66-h cells compared with 18-h cells (∼70{\%} greater). Cytotrophoblast cells exhibit an [ATP]o-stimulated Ca2+-activated K+ efflux. The dependency of this pathway on [Ca2+]o is greater in the 66-h multinucleate syncytiotrophoblast-like cells, suggesting that the mechanism for Ca2+ entry may be altered during differentiation of trophoblast cells.",
keywords = "Calcium entry, Human placenta, Intermediate calcium-activated potassium channel",
author = "Clarson, {L. H.} and Victoria Roberts and Greenwood, {S. L.} and Elliott, {A. C.}",
year = "2002",
language = "English (US)",
volume = "282",
journal = "American Journal of Physiology - Renal Fluid and Electrolyte Physiology",
issn = "1931-857X",
publisher = "American Physiological Society",
number = "4 51-4",

}

TY - JOUR

T1 - ATP-stimulated Ca2+-activated K+ efflux pathway and differentiation of human placental cytotrophoblast cells

AU - Clarson, L. H.

AU - Roberts, Victoria

AU - Greenwood, S. L.

AU - Elliott, A. C.

PY - 2002

Y1 - 2002

N2 - The aim of this study was to determine whether extracellular ATP ([ATP]o) stimulated a Ca2+-activated K+ efflux in trophoblast cells that was dependent on extracellular Ca2+ ([Ca2+]o). Cytotrophoblast cells, isolated from human placenta, were examined following 18 h (relatively undifferentiated) and 66 h (multinucleate cells) of culture. Potassium efflux was measured using 86Rb as a trace marker. Intracellular Ca2+ ([Ca2+]i) was examined by microfluorometry using fura 2. [ATP]o significantly increased 86Rb efflux to a peak that declined to control (18-h cells) or an elevated plateau (66-h cells) and was inhibited by 100 nM charybdotoxin. Removing [Ca2+]o significantly reduced 86Rb efflux in both groups as did application of 150 μM GdCl3. [ATP]o significantly increased [Ca2+]i in both groups of cells. The response was reduced by removing [Ca2+]o and applying 150 μM GdCl3. For both 86Rb efflux and microfluorometry experiments, the response to [ATP]o was more dependent on [Ca2+]o in 66-h cells compared with 18-h cells (∼70% greater). Cytotrophoblast cells exhibit an [ATP]o-stimulated Ca2+-activated K+ efflux. The dependency of this pathway on [Ca2+]o is greater in the 66-h multinucleate syncytiotrophoblast-like cells, suggesting that the mechanism for Ca2+ entry may be altered during differentiation of trophoblast cells.

AB - The aim of this study was to determine whether extracellular ATP ([ATP]o) stimulated a Ca2+-activated K+ efflux in trophoblast cells that was dependent on extracellular Ca2+ ([Ca2+]o). Cytotrophoblast cells, isolated from human placenta, were examined following 18 h (relatively undifferentiated) and 66 h (multinucleate cells) of culture. Potassium efflux was measured using 86Rb as a trace marker. Intracellular Ca2+ ([Ca2+]i) was examined by microfluorometry using fura 2. [ATP]o significantly increased 86Rb efflux to a peak that declined to control (18-h cells) or an elevated plateau (66-h cells) and was inhibited by 100 nM charybdotoxin. Removing [Ca2+]o significantly reduced 86Rb efflux in both groups as did application of 150 μM GdCl3. [ATP]o significantly increased [Ca2+]i in both groups of cells. The response was reduced by removing [Ca2+]o and applying 150 μM GdCl3. For both 86Rb efflux and microfluorometry experiments, the response to [ATP]o was more dependent on [Ca2+]o in 66-h cells compared with 18-h cells (∼70% greater). Cytotrophoblast cells exhibit an [ATP]o-stimulated Ca2+-activated K+ efflux. The dependency of this pathway on [Ca2+]o is greater in the 66-h multinucleate syncytiotrophoblast-like cells, suggesting that the mechanism for Ca2+ entry may be altered during differentiation of trophoblast cells.

KW - Calcium entry

KW - Human placenta

KW - Intermediate calcium-activated potassium channel

UR - http://www.scopus.com/inward/record.url?scp=0036087475&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036087475&partnerID=8YFLogxK

M3 - Article

VL - 282

JO - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

JF - American Journal of Physiology - Renal Fluid and Electrolyte Physiology

SN - 1931-857X

IS - 4 51-4

ER -