In situ hybridization of h,k-atpase [beta] subunit mrna in rat and rabbit kidney. Campbell-Thompson, Martha L., Jill W. Verlander, Kevin A. Curran, W. Grady Campbell, Brian D. Cain, Charles S. Wingo, and James E. McGuigan. Division of Gastroenterology, Hepatology, and Nutrition, Division of Nephrology, Hypertension, and Transplantation, and Department of Biochemistry and Molecular Biology, University of Florida College of Medicine, Gainesville, FL, 32610
APStracts 2:0060F, 1995.
Through a variety of techniques, several investigators have demonstrated the presence of an H,K-ATPase enzyme in the renal collecting duct, suggesting that this enzyme serves an important physiological role in the regulation of acid-base balance and potassium excretion by the kidney. The present study was designed to localize cells expressing H,K-ATPase [beta] subunit mRNA in rat and rabbit kidney by nonradioactive in situ hybridization. A 570-bp DNA fragment of rabbit renal H,K-ATPase [beta] subunit was used to produce digoxigenin-labeled riboprobes by in vitro transcription. Northern blot hybridization demonstrated transcripts in rat gastric oxyntic mucosa and kidney. In situ hybridization on kidney tissue sections demonstrated H,K-ATPase [beta] subunit mRNA localization in epithelial cells, including intercalated cells in the connecting segment and cortical and medullary collecting duct, principal cells in the inner stripe of the outer medullary collecting duct, and inner medullary collecting duct cells in both the rat and the rabbit. These observations provide evidence that H,K-ATPase [beta] subunit mRNA is present throughout the collecting duct of the kidney. The distribution of this message is consistent with a role for H,K-ATPase in bicarbonate absorption in both the outer and inner medullary collecting duct.

Received 9 June 1994; accepted in final form 3 April 1995.
APS Manuscript Number F191-4.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 April 1995.