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[Effects of theophylline on ion transport in rabbit tracheal epithelium]

K Ichimura1, T Majima, T Horie

  • 1First Department of Internal Medicine, Nihon University School of Medicine, 30-1 Ohyaguchi-kamimachi, Itabashi-ku, Tokyo 173-0032, Japan.

Nihon Kokyuki Gakkai Zasshi = the Journal of the Japanese Respiratory Society
|January 26, 2008
PubMed

Insights

Theophylline stimulates chloride secretion in rabbit tracheal epithelium by activating cAMP-dependent channels on the mucosal side. This finding clarifies theophylline's cellular mechanisms in treating asthma.

Area of Science:

  • Respiratory Physiology
  • Cellular Biology
  • Pharmacology

Context:

  • Theophylline is a bronchodilator and anti-inflammatory agent used for asthma.
  • Its precise cellular mechanisms, particularly regarding ion transport in the airway epithelium, remain incompletely understood.

Purpose:

  • To investigate the effect of theophylline on ion transport in rabbit tracheal epithelium.
  • To elucidate the specific ion channels and pathways involved in theophylline's action.

Summary:

  • Theophylline applied to the mucosal side of rabbit tracheal epithelium dose-dependently increased short-circuit current (Isc), indicating active ion transport.
  • This increase was inhibited by diphenylamine 2-carboxylate, a chloride channel blocker, but not by amiloride (sodium channel blocker) or a calcium-dependent chloride channel blocker.
  • These findings suggest theophylline stimulates cAMP-dependent chloride channels, promoting chloride secretion.

Impact:

  • Provides a clearer understanding of theophylline's cellular effects on airway epithelium.
  • Identifies specific ion channels (cAMP-dependent chloride channels) mediating theophylline's action.
  • Contributes to the knowledge base for developing more targeted asthma therapies.

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