Please use this identifier to cite or link to this item:
Title: cAMP inhibits transepithelial chloride secretion across bovine ciliary body/epithelium
Authors: Do, CW
Kong, CW
To, CH 
Issue Date: 2004
Source: Investigative ophthalmology and visual science, 2004, v. 45, no. 10, p. 3638-3643
Abstract: PURPOSE. To investigate the potential significance of cAMP in the regulation of Cl- transport across the bovine ciliary body/epithelium (CBE). METHODS. Fresh native bovine CBE preparation was mounted in a modified Ussing chamber. The effects of cAMP-stimulating agents on short-circuit current (Isc) and net 36Cl- secretion were determined. RESULTS. Addition of cAMP-stimulating agents inhibited net Cl- secretion. Forskolin, when added bilaterally, reduced Cl- secretion by 60%. Similarly, bilateral isoproterenol or vasoactive intestinal peptide inhibited Cl- transport by 15% and 37%, respectively, suggesting a cAMP-sensitive Cl- transport across the ciliary epithelium. This notion was supported by the exogenous application of 8-bromo-cAMP (8-Br-cAMP) or 3-isobutyl-1-methylxanthine (IBMX), which reduced the net Cl- secretion by 49% and 85%, respectively. In unstimulated preparations, addition of 5-nitro-2(3-phenylpropylamino)-benzoic acid (NPPB) to the blood side had no effects on Isc and net Cl- transport, indicating that Cl- reabsorption was negligible under baseline conditions. Also, pretreatment with NPPB from the blood side did not prevent forskolin-induced Isc inhibition, suggesting that the inhibition of Cl- transport did not result from the facilitation of Cl- reabsorption. However, pretreatment with heptanol from both sides completely blocked the forskolin-induced Isc inhibition, suggesting that cAMP may reduce Cl- transport by uncoupling the intercellular gap junctions. CONCLUSIONS. The results suggest that cAMP plays a crucial role in modulating Cl- secretion across the ciliary epithelium. The effect is possibly mediated, at least in part, by the regulation of the permeability of gap junctions between pigmented and nonpigmented ciliary epithelial cells.
Publisher: Association for Research in Vision and Ophthalmology
Journal: Investigative ophthalmology and visual science 
ISSN: 0146-0404
EISSN: 1552-5783
DOI: 10.1167/iovs.03-1343
Appears in Collections:Journal/Magazine Article

View full-text via PolyU eLinks SFX Query
Show full item record


Last Week
Last month
Citations as of Sep 2, 2020


Last Week
Last month
Citations as of Sep 17, 2020

Page view(s)

Last Week
Last month
Citations as of Sep 15, 2020

Google ScholarTM



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.