Hypotonicity activates a native chloride current in Xenopus oocytes

Michael John Ackerman, Kevin D. Wickman, David E. Clapham

Research output: Contribution to journalArticle

201 Citations (Scopus)

Abstract

Xenopus oocytes are frequently utilized for in vivo expression of cellular proteins, especially ion channel proteins. A thorough understanding of the endogenous conductances and their regulation is paramount for proper characterization of expressed channel proteins. Here we detail a novel chloride current (I(Cl.swell)) responsive to hypotonicity in Xenopus oocytes using the two-electrode voltage clamp technique. Reducing the extracellular osmolarity by 50% elicited a calcium-independent chloride current having an anion conductivity sequence identical with swelling-induced chloride currents observed in epithelial cells. The hypotonicity-activated current was blocked by chloride channel blockers, trivalent lanthanides, and nucleotides. G- protein, cAMP-PKA, and arachidonic acid signaling cascades were not involved in I(Cl.swell) activation. I(Cl.swell) is distinct from both stretch- activated nonselective cation channels and the calcium-activated chloride current in oocytes and may play a critical role in volume regulation in Xenopus oocytes.

Original languageEnglish (US)
Pages (from-to)153-179
Number of pages27
JournalJournal of General Physiology
Volume103
Issue number2
StatePublished - Feb 1994

Fingerprint

Xenopus
Oocytes
Chlorides
Chloride Channels
Lanthanoid Series Elements
Calcium Chloride
Proteins
Patch-Clamp Techniques
Ion Channels
GTP-Binding Proteins
Arachidonic Acid
Osmolar Concentration
Anions
Cations
Electrodes
Nucleotides
Epithelial Cells

ASJC Scopus subject areas

  • Physiology

Cite this

Hypotonicity activates a native chloride current in Xenopus oocytes. / Ackerman, Michael John; Wickman, Kevin D.; Clapham, David E.

In: Journal of General Physiology, Vol. 103, No. 2, 02.1994, p. 153-179.

Research output: Contribution to journalArticle

Ackerman, Michael John ; Wickman, Kevin D. ; Clapham, David E. / Hypotonicity activates a native chloride current in Xenopus oocytes. In: Journal of General Physiology. 1994 ; Vol. 103, No. 2. pp. 153-179.
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