Monoclonal antibody against conductive chloride transport in pig
ileal apical membrane vesicles.
Racette, Kenneth J, Kim J Gaspar, George W Forsyth.
Veterinary Physiological Sciences, 52 Campus Drive, University of
Saskatchewan, Saskatoon, SK S7N 5B4
APStracts 3:0062C, 1996.
Conductive chloride transport in the small intestine is an important
factor controlling fluid movement from the blood to the lumen of the
gut. Several proteins with potential conductive chloride ion channel
activity are expressed in the enterocyte cell population. However, it
is not clear whether one, or more than one protein species is
normally responsible for mediating conductive chloride transport. We
have raised monoclonal antibodies that inhibit conductive chloride
transport in apical membrane vesicles prepared from porcine ileal
enterocytes. These monoclonal antibodies have been used to identify a
unique protein involved with this conductive chloride transport. Here
we report that anti-chloride conductance monoclonal antibodies did
not detect any antigen in Western blots of enterocyte apical membrane
protein. Dot blotting and immunoprecipitation experiments indicated
that the antigen recognized by these monoclonal antibodies was not
the cystic fibrosis transmembrane conductance regulator (CFTR). The
antigen was localized to both villus and crypt regions of ileum on
immunohistochemistry. A 90 kDa protein species was immunoprecipitated
from a primary enterocyte cell line by these monoclonal antibodies.
This 90 kDa protein may be a chloride ion channel, or may play some
regulatory role in conductive chloride transport in enterocyte apical
membrane vesicles.
Received 10 November 1995; accepted in final form 9 February
1996.
APS Manuscript Number C682-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96