Cyclic AMP modulation of active ion transport in the pigmented rabbit conjunctiva.
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.
Kompella
U B
UB
Department of Pharmaceutical Sciences, School of Pharmacy, University of Southern California, Los Angeles, USA.
Kim
K J
KJ
Shiue
M H
MH
Lee
V H
VH
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002712:Chlorides / Q000378:metabolism*; D005576:Colforsin / Q000494:pharmacology; D003228:Conjunctiva / Q000187:drug effects / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D004837:Epinephrine / Q000494:pharmacology; D017136:Ion Transport; D008297:Male; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D011817:Rabbits; D013726:Terbutaline / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D002712:Chlorides; D010726:Phosphodiesterase Inhibitors; D005576:Colforsin; D015124:8-Bromo Cyclic Adenosine Monophosphate; D013806:Theophylline; D000242:Cyclic AMP; D013726:Terbutaline; D004837:Epinephrine