Please use this identifier to cite or link to this item:
Title: Model of ionic transport for bovine ciliary epithelium : effects of acetazolamide and HCO3 -
Authors: To, CH 
Do, CW
Zamudio, AC
Candia, OA
Keywords: Aqueous humor secretion
Bicarbonate fluxes
Chloride fluxes
Short-circuit current
Ussing chamber
Issue Date: 2001
Publisher: American Physiological Society
Source: American journal of physiology. Cell physiology, 2001, v. 280, no. 6 49-6, p. c1521-c1530 How to cite?
Journal: American journal of physiology. Cell physiology 
Abstract: The possible existence of transepithelial bicarbonate transport across the isolated bovine ciliary body was investigated by employing a chamber that allows for the measurement of unidirectional, radio-labeled fluxes of CO2 + HCO3 -. No net flux of HCO3 - was detected. However, acetazolamide (0.1 mM) reduced the simultaneously measured short-circuit current (Isc). In other experiments in which 36Cl- was used, a net Cl- flux of 1.12 μeq·h-1·cm-2 (30 μA/cm2) in the blood-to-aqueous direction was detected. Acetazolamide, as well as removal of HCO3 - from the aqueous bathing solution, inhibited the net Cl- flux and Isc. Because such removal should increase HCO3 - diffusion toward the aqueous compartment and increase the Isc, this paradoxical effect could result from cell acidification and partial closure of Cl- channels. The acetazolamide effect on Cl- fluxes can be explained by a reduction of cellular H+ and HCO3 - (generated from metabolic CO2 production), which exchange with Na+ and Cl- via Na+/H+ and Cl-/HCO3 - exchangers, contributing to the net Cl- transport. The fact that the net Cl- flux is about three times larger than the Isc is explained with a vectorial model in which there is a secretion of Na+ and K+ into the aqueous humor that partially subtracts from the net Cl- flux. These transport characteristics of the bovine ciliary epithelium suggest how acetazolamide reduces intraocular pressure in the absence of HCO3 - transport as a driving force for fluid secretion.
ISSN: 0363-6143
EISSN: 1522-1563
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 Jul 7, 2018


Last Week
Last month
Citations as of Jul 10, 2018

Page view(s)

Last Week
Last month
Citations as of Jul 15, 2018

Google ScholarTM


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