Regional and segmental localization of ae2 anion exchanger mrna and
protein in rat kidney.
Brosius, Frank C., Khanh Nguyen, A. K. Stuart-Tilley, C. Haller,
Josephine P. Briggs, and S. L. Alper.
Renal Division and Dept. of Medicine, Ann Arbor Veterans Affairs
Medical Center, and Univ. of Michigan, Ann Arbor, MI; Molecular
Medicine and Renal Units, Beth Israel Hospital, and Depts. of
Medicine and Cell Biology, Harvard Medical School, Boston, MA.
APStracts 2:0081F, 1995.
Chloride/base exchange activity has been detected in every mammalian
nephron segment in which it has been sought. However, in contrast to
the Cl/HCO3- exchanger AE1 in Type A intercalated cells, localization
of AE2 within the kidney has not been reported. We therefore studied
AE2 expression in rat kidney. AE2 mRNA was present in cortex, outer
medulla, and inner medulla. Semiquantitative PCR of cDNA from
microdissected tubules revealed AE2 cDNA levels (copies cDNA derived
per mm tubule, mean + s.e.m): proximal convoluted tubule (PCT),
688+161; proximal straight tubule (PST), 652+189; medullary thick
ascending limb (MTAL) 1378+226; cortical thick ascending limb (CTAL),
741+24; cortical collecting duct (CCD) 909+71, and outer medullary
collecting duct (OMCD) 579+132. AE2 cDNA was also amplified in thin
limbs and in inner medullary collecting duct (IMCD). AE2 polypeptide
was detected in all kidney regions. AE2 mRNA and protein were also
detected in several renal cell lines. The data are compatible with
AE2's postulated roles in maintenance of intracellular pH and
chloride concentration, and with its possible participation in
transepithelial transport.
Received 12 December 1994; accepted in final form 3 April 1995.
APS Manuscript Number F438-4.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 26 May 1995.