Regulation of ae2 cl:hco3 exchanger during intestinal
development.
Chow, Alice, Wei Zhou, and Ross Jacobson.
Department of Medicine, Emory University School of Medicine,
Atlanta, Georgia 30322
APStracts 3:0038G, 1996.
The sodium-independent Cl:HCO3 exchangers in many tissues are encoded
by AE2, which is a member of the Anion Exchanger (AE) gene family.
Molecular regulation of AE2 remains mostly unknown. In this study,
AE2 mRNA levels during enterocyte differentiation and intestinal
development were examined in rat small intestines. AE2 mRNA levels
did not show obvious segmental variation or vary along the crypt
-villus axis. In contrast, AE2 mRNA decreased between days 14 and 21
after birth, the period corresponding to the transition period
between the suckling and the weanling stages in rats. Effects of L
-thyroxine and dexamethasone on AE2 expression were examined because
these hormones play important roles in gene regulation during
development. L-thyroxine administration starting on day 9 after birth
led to an approximately 60% decrease (p<0.001) in AE2 mRNA on
day 13. Dexamethasone had no effect on AE2 mRNA level regardless of
whether the hormone was administered alone or in conjunction with L
-thyroxine. Our results indicate that AE2 mRNA in the intestine is
regulated during development and this regulation may in part be
related to hormonal changes.
Received 25 March 1994; accepted in final form 2 February 1996.
APS Manuscript Number G114-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 14 February 96