Regulation of cloned, Ca2+-activated K+ channels by cell volume changes.

Morten Grunnet; Nanna MacAulay; Nanna K Jorgensen; Skaaning Jensen; Søren-Peter Olesen; Dan A Klaerke

doi:10.1007/s00424-002-0782-4

Regulation of cloned, Ca2+-activated K+ channels by cell volume changes.

Morten Grunnet, Nanna MacAulay, Nanna K Jorgensen, Skaaning Jensen, Søren-Peter Olesen, Dan A Klaerke

Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › peer review

46 Citationer (Scopus)

Abstract

Udgivelsesdato: 2002-May

Originalsprog	Engelsk
Tidsskrift	Pflügers Archiv: European Journal of Physiology
Vol/bind	444
Udgave nummer	1-2
Sider (fra-til)	167-77
Antal sider	10
ISSN	0031-6768
DOI	https://doi.org/10.1007/s00424-002-0782-4
Status	Udgivet - 2002

Bibliografisk note

Keywords: Animals; Aquaporin 1; Aquaporins; Cell Size; Cloning, Molecular; Cytochalasin D; Electrophysiology; Nucleic Acid Synthesis Inhibitors; Oocytes; Osmolar Concentration; Patch-Clamp Techniques; Potassium Channels, Calcium-Activated; Xenopus laevis

Adgang til dokumentet

10.1007/s00424-002-0782-4

Citationsformater

@article{d7f04300ab5511ddb5e9000ea68e967b,

title = "Regulation of cloned, Ca2+-activated K+ channels by cell volume changes.",

abstract = "Ca2+-activated K+ channels of big (hBK), intermediate (hIK) or small (rSK3) conductance were co-expressed with aquaporin 1 (AQP1) in Xenopus laevis oocytes. hBK channels were activated by depolarization, whereas hIK and rSK3 channels were activated by direct injection of Ca2+ or Cd2+ into the oocyte cytoplasm, before the oocytes were subjected to hyperosmolar or hypoosmolar (+/-50 mOsm mannitol) challenges. In all cases, the oocytes responded rapidly to the osmotic changes with shrinkage or swelling and the effects on the K+ currents were measured. hIK and rSK3 currents were highly sensitive to volume changes and increased immediately to 178% (hIK) or 165% (rSK3) of control in response to swelling and decreased to 64% (hIK) or 61% (rSK3) of control after shrinkage. These responses were dependent on the channels being pre-activated and were almost totally abolished after injection of cytochalasin D into the oocyte cytoplasm (final concentration: 1 microM). In contrast, hBK channels showed only a minor sensitivity to volume changes; the hBK channel activity decreased approximately 20% after swelling and increased approximately 20% after shrinkage. The opposite effects of volume changes on hIK/rSK3 and hBK channels suggest that the significant stimulation of hIK and rSK3 channels during swelling is not mediated by changes in intracellular Ca2+, but rather through interactions with the cytoskeleton, provided that a sufficient basal concentration of intracellular Ca2+ or Cd2+ is present.",

author = "Morten Grunnet and Nanna MacAulay and Jorgensen, {Nanna K} and Skaaning Jensen and S{\o}ren-Peter Olesen and Klaerke, {Dan A}",

note = "Keywords: Animals; Aquaporin 1; Aquaporins; Cell Size; Cloning, Molecular; Cytochalasin D; Electrophysiology; Nucleic Acid Synthesis Inhibitors; Oocytes; Osmolar Concentration; Patch-Clamp Techniques; Potassium Channels, Calcium-Activated; Xenopus laevis",

year = "2002",

doi = "10.1007/s00424-002-0782-4",

language = "English",

volume = "444",

pages = "167--77",

journal = "Pfl{\"u}gers Archiv: European Journal of Physiology",

issn = "0031-6768",

publisher = "Springer",

number = "1-2",

}

TY - JOUR

T1 - Regulation of cloned, Ca2+-activated K+ channels by cell volume changes.

AU - Grunnet, Morten

AU - MacAulay, Nanna

AU - Jorgensen, Nanna K

AU - Jensen, Skaaning

AU - Olesen, Søren-Peter

AU - Klaerke, Dan A

N1 - Keywords: Animals; Aquaporin 1; Aquaporins; Cell Size; Cloning, Molecular; Cytochalasin D; Electrophysiology; Nucleic Acid Synthesis Inhibitors; Oocytes; Osmolar Concentration; Patch-Clamp Techniques; Potassium Channels, Calcium-Activated; Xenopus laevis

PY - 2002

Y1 - 2002

N2 - Ca2+-activated K+ channels of big (hBK), intermediate (hIK) or small (rSK3) conductance were co-expressed with aquaporin 1 (AQP1) in Xenopus laevis oocytes. hBK channels were activated by depolarization, whereas hIK and rSK3 channels were activated by direct injection of Ca2+ or Cd2+ into the oocyte cytoplasm, before the oocytes were subjected to hyperosmolar or hypoosmolar (+/-50 mOsm mannitol) challenges. In all cases, the oocytes responded rapidly to the osmotic changes with shrinkage or swelling and the effects on the K+ currents were measured. hIK and rSK3 currents were highly sensitive to volume changes and increased immediately to 178% (hIK) or 165% (rSK3) of control in response to swelling and decreased to 64% (hIK) or 61% (rSK3) of control after shrinkage. These responses were dependent on the channels being pre-activated and were almost totally abolished after injection of cytochalasin D into the oocyte cytoplasm (final concentration: 1 microM). In contrast, hBK channels showed only a minor sensitivity to volume changes; the hBK channel activity decreased approximately 20% after swelling and increased approximately 20% after shrinkage. The opposite effects of volume changes on hIK/rSK3 and hBK channels suggest that the significant stimulation of hIK and rSK3 channels during swelling is not mediated by changes in intracellular Ca2+, but rather through interactions with the cytoskeleton, provided that a sufficient basal concentration of intracellular Ca2+ or Cd2+ is present.

AB - Ca2+-activated K+ channels of big (hBK), intermediate (hIK) or small (rSK3) conductance were co-expressed with aquaporin 1 (AQP1) in Xenopus laevis oocytes. hBK channels were activated by depolarization, whereas hIK and rSK3 channels were activated by direct injection of Ca2+ or Cd2+ into the oocyte cytoplasm, before the oocytes were subjected to hyperosmolar or hypoosmolar (+/-50 mOsm mannitol) challenges. In all cases, the oocytes responded rapidly to the osmotic changes with shrinkage or swelling and the effects on the K+ currents were measured. hIK and rSK3 currents were highly sensitive to volume changes and increased immediately to 178% (hIK) or 165% (rSK3) of control in response to swelling and decreased to 64% (hIK) or 61% (rSK3) of control after shrinkage. These responses were dependent on the channels being pre-activated and were almost totally abolished after injection of cytochalasin D into the oocyte cytoplasm (final concentration: 1 microM). In contrast, hBK channels showed only a minor sensitivity to volume changes; the hBK channel activity decreased approximately 20% after swelling and increased approximately 20% after shrinkage. The opposite effects of volume changes on hIK/rSK3 and hBK channels suggest that the significant stimulation of hIK and rSK3 channels during swelling is not mediated by changes in intracellular Ca2+, but rather through interactions with the cytoskeleton, provided that a sufficient basal concentration of intracellular Ca2+ or Cd2+ is present.

U2 - 10.1007/s00424-002-0782-4

DO - 10.1007/s00424-002-0782-4

M3 - Journal article

C2 - 11976929

SN - 0031-6768

VL - 444

SP - 167

EP - 177

JO - Pflügers Archiv: European Journal of Physiology

JF - Pflügers Archiv: European Journal of Physiology

IS - 1-2

ER -