Nhe2 and nhe3 are human and rabbit intestinal brush border
proteins.
Hoogerwerf, W. Alexandra, Su C. Tsao, Olivier Devuyst, Susan A Levine,
C. H. Chris Yun, Jeannie W. Yip, Michael E. Cohen, Patricia D.
Wilson, Audrey J. Lazenby, Chung-Ming Tse, and Mark Donowitz.
Departments of Med., Path. and Physiol., GI and Renal Div., The
Johns Hopkins Univ. School of Medicine, Baltimore, MD
APStracts 2:0124G, 1995.
Rabbit NHE2 and NHE3 are two epithelial isoform Na+/H+ exchangers
(NHE), the messages for which are found predominantly and entirely,
respectively, in renal, intestinal and gastric mucosa. The current
studies used Western analysis and immunohistochemistry to identify
and characterize the apical vs basolateral membrane distribution of
NHE2 and NHE3 in intestinal epithelial cells. Based on Western
analysis, NHE2 and NHE3 both are present in brush border but not
basolateral membranes of small intestine. Both NHE2 and NHE3 are 85kD
proteins. Consistent with Western analysis, NHE2 and NHE3 are
immunolocalized to the brush border but not basolateral membranes of
villus epithelial cells but not goblet cells in human jejunum and
ileum, and in surface epithelial cells in the ascending and
descending colon and rectum. In addition, NHE2 and NHE3 are present
in small amounts in the crypt cell brush border of human jejunum,
ileum, ascending and descending colon and rectum. In rabbit jejunum,
ileum, and ascending colon, NHE2 and NHE3 are present in the brush
border of epithelial and not goblet cells, again much more in the
villus (small intestine)/surface cells (colon) than the crypt. NHE2
but not NHE3 is present in brush border of rabbit descending colon
surface cells and in small amounts in crypt cells. NHE2 and NHE3 are
both human and rabbit small intestinal and colonic epithelial cell
brush border Na+/H+ exchanger isoforms, which co-localize in all
intestinal segments except rabbit descending colon, which lacks NHE3.
Received 23 May 1994; accepted in final form 8 June 1995.
APS Manuscript Number G192-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 11 July 1995.