In:
American Journal of Physiology-Cell Physiology, American Physiological Society, Vol. 259, No. 5 ( 1990-11-01), p. C752-C761
Abstract:
Rat and human pancreatic duct cells have small-conductance Cl- channels in their apical plasma membranes. These channels are regulated by secretin and adenosine 3',5'-cyclic monophosphate and may function in parallel with Cl(-)-HCO3- exchangers to allow HCO3- secretion from the duct cell. Using the patch-clamp technique, we have now determined the anion permeability sequence of the channel as NO3- greater than Br- approximately I- approximately Cl- much greater than HCO3- much greater than gluconate. From this we conclude 1) that anion permeation involves a weak interaction with charged sites inside the channel pore, 2) that because of the low HCO3-/Cl- permeability ratio it is unlikely that significant amounts of HCO3- could be secreted directly via the channel, and 3) that channel permeability may determine the anion selectivity of secretion. We also show that 5-nitro-2-(3-phenylpropylamino)benzoic acid blocks the small-conductance Cl- channel, whereas 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid has no effect.
Type of Medium:
Online Resource
ISSN:
0363-6143
,
1522-1563
DOI:
10.1152/ajpcell.1990.259.5.C752
Language:
English
Publisher:
American Physiological Society
Publication Date:
1990
detail.hit.zdb_id:
1477334-X
SSG:
12
Permalink