A potassium current activated by lemakalim and metabolic inhibition in rabbit mesenteric artery

Shai D. Silberberg, Cornelis van Breemen

Research output: Contribution to journalArticlepeer-review

47 Scopus citations

Abstract

K+ channels which are inhibited by intracellular ATP (ATPi) (KATP channels) are thought to be the physiological target site of the K+ channel opening drugs (2) and to underlie a variety of physiological phenomena including hypoxia induced vasodilation (3). However, electrophysiological evidence for ATPi-regulated K+ currents in smooth muscle is scarce. We, therefore, investigated the effects of one K+ channel opener, lemakalim, and metabolic inhibition on the membrane conductance of freshly dissociated rabbit mesenteric artery smooth muscle cells, using the perforated-patch whole cell recording technique (6). The cells were metabolically inhibited with 1 mM iodoacetic acid and 50 μM dinitrophenol. Both lemakalim (0.1-3 μM) and metabolic inhibition activated a time-independent and glyburide sensitive K+ current at physiological membrane potentials. The similarities between the lemakalim and metabolic inhibition activated currents suggest that a single class of channels underlies both currents. These results are the first whole-cell current recordings to demonstrate the activation of a smooth muscle membrane conductance by metabolic inhibition, lending support to the view that hypoxia induced vasodilation arises from the activation of KATP channels.

Original languageEnglish
Pages (from-to)118-120
Number of pages3
JournalPflugers Archiv European Journal of Physiology
Volume420
Issue number1
DOIs
StatePublished - 1 Jan 1992
Externally publishedYes

Keywords

  • K current
  • metabolic inhibition
  • smooth muscle

Fingerprint

Dive into the research topics of 'A potassium current activated by lemakalim and metabolic inhibition in rabbit mesenteric artery'. Together they form a unique fingerprint.

Cite this