Hypotonic solution increases the slowly activating potassium current IsK expressed in Xenopus oocytes

Andreas E. Busch, Michael Varnum, John P. Adelman, R. Alan North

Research output: Contribution to journalArticlepeer-review

44 Scopus citations


A slowly activating potassium current was expressed in Xenopus oocytes by injection of RNA transcribed from a rat kidney cDNA clone. Hypotonic solutions (160 mOsmol/l; control was 220 mOsmol/l) increased the current by increasing the rate of activation and by decreasing the depolarization needed to activate the current. This effect of hypotonicity was not observed in calcium-free solution, but was unaffected by staurosporine or the calmodulin antagonist W7. Cytochalasin D reduced the current and prevented the increase by hypotonic solution. The results suggest that the increase in this potassium current by hypotonic solution might result from calcium entry and changes in the actin network.

Original languageEnglish (US)
Pages (from-to)804-810
Number of pages7
JournalBiochemical and Biophysical Research Communications
Issue number2
StatePublished - Apr 30 1992

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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