Cyclic AMP modulation of active ion transport in the pigmented rabbit conjunctiva

J Ocul Pharmacol Ther. Fall 1996;12(3):281-7. doi: 10.1089/jop.1996.12.281.

Abstract

This study was conducted to determine whether active ion transport in the pigmented rabbit conjunctiva was subjected to cyclic AMP modulation. 8-BrcAMP and compounds that may affect intracellular cAMP levels were tested for their effects on the conjunctival short-circuit current (Isc) following mucosal application. Conjunctival Isc was increased by 1 mM 8-BrcAMP, 0.001-20 microM forskolin, 0.01-2 mM theophylline, 2 microM 1-epinephrine, and 20 microM terbutaline in a Cl(-)-containing but not in a Cl(-)-free medium. The increase in Isc induced by 1 mM 8-BrcAMP was reversed by 1 mM N-phenylanthranilic acid, suggesting enhancement of Cl- secretion by cAMP. Similarly, the increase in Isc induced by 20 microM terbutaline was blunted by 1 microM timolol, suggesting a role for beta 2 adrenergic modulation of Cl- secretion. Collectively, these results are consistent with the notion of cAMP modulation of conjunctival active ion transport.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 8-Bromo Cyclic Adenosine Monophosphate / pharmacology
  • Adrenergic beta-Agonists / pharmacology
  • Adrenergic beta-Antagonists / pharmacology
  • Animals
  • Biological Transport, Active
  • Calcium Channel Blockers / pharmacology
  • Chlorides / metabolism*
  • Colforsin / pharmacology
  • Conjunctiva / drug effects
  • Conjunctiva / metabolism*
  • Cyclic AMP / metabolism*
  • Epinephrine / pharmacology
  • Ion Transport
  • Male
  • Phosphodiesterase Inhibitors / pharmacology
  • Rabbits
  • Terbutaline / pharmacology
  • Theophylline / pharmacology

Substances

  • Adrenergic beta-Agonists
  • Adrenergic beta-Antagonists
  • Calcium Channel Blockers
  • Chlorides
  • Phosphodiesterase Inhibitors
  • Colforsin
  • 8-Bromo Cyclic Adenosine Monophosphate
  • Theophylline
  • Cyclic AMP
  • Terbutaline
  • Epinephrine