Non-coordinated expression of alpha, [beta], and [gamma] sub-unit
mrnas of the epithelial sodium channel along the rat respiratory
tract.
Farman, N., C. R. Talbot, R. Boucher, M. Fay, C. Canessa, B. Rossier,
and J. P. Bonvalet.
Inserm U246, Facult[acute]e de M[acute]edecine X. Bichat, 75018
Paris, France, *Division of Pulmonary Diseases, University of North
Carolina, Chapel Hill, North Carolina 27599-7020, USA, and Institut
de Pharmacologie et de Toxicologie, Universit[acute]e de Lausanne, CH
1005 Lausanne, Suisse
APStracts 3:0275C, 1996.
Sodium reabsorption from the epithelial surface of the respiratory
tract plays a fundamental role in respiratory physiology. As in the
epithelia of the renal collecting tubule and distal colon, sodium
enters across the luminal surface of respiratory epithelial cells via
a recently cloned amiloride-sensitive, multi-subunit ( [alpha],
[beta], [tau]) epithelial sodium channel (ENaC). We have examined the
cellular expression at the mRNA level of the [alpha], [beta], and
[gamma] sub-units of rENaC in the rat lung and upper airways
epithelial cells using in situ hybridization. A large prevalence of
[alpha] and [gamma] rENAC sub-unit expression (over [beta]) was found
in tracheal epithelium, in a sub- population of alveolar cells,
presumably type II pneumocytes, and in nasal and tracheal gland
acini. In contrast, equivalent levels of expression of all three sub
-units were detected in bronchiolar epithelium and in rat nasal gland
ducts. This diversity of expression may reflect cell-specific
functions of the amiloride-sensitive sodium channel along the
respiratory tract.
Received 14 May 1996; accepted in final form 15 August 1996.
APS Manuscript Number C261-6.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 29 August 1996