Hypoxic suppression of K+ currents in type I carotid body cells: selective effect on the Ca2(+)-activated K+ current

Neurosci Lett. 1990 Nov 13;119(2):253-6. doi: 10.1016/0304-3940(90)90846-2.

Abstract

Whole-cell K+ currents were recorded in isolated type I carotid body cells using the patch-clamp technique. Hypoxia (pO2 25 torr) reversibly suppressed K+ currents in a voltage-dependent manner: maximal effects were seen at low, positive test potentials, where the Ca2(+)-activated component of K+ currents was greatest. Enhancing this component with 5 microM BAY K 8644 exaggerated the effects of hypoxia, and when the component was inhibited (100 microM Cd2+ or 5 microM nifedipine) hypoxic effects were abolished. As hypoxia does not affect Ca2+ currents directly, these data indicate the suppressive effect of hypoxia is selective for the Ca2(+)-activated component of K+ currents in type I cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / pharmacology
  • Animals
  • Cadmium / pharmacology
  • Calcium / pharmacology*
  • Calcium Channel Blockers / pharmacology
  • Carotid Body / cytology
  • Carotid Body / physiopathology*
  • Dihydropyridines / metabolism
  • Electrophysiology
  • Hypoxia / physiopathology*
  • Nifedipine / pharmacology
  • Potassium / physiology*
  • Rats

Substances

  • Calcium Channel Blockers
  • Dihydropyridines
  • Cadmium
  • 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester
  • 1,4-dihydropyridine
  • Nifedipine
  • Potassium
  • Calcium