Identification and function of a1 adenosine receptors in normal and
cystic fibrosis human airway epithelial cells.
McCoy, David E., Erik M. Schwiebert, Katherine H. Karlson*, William S.
Spielman, and Bruce A. Stanton.
Department of Physiology, Dartmouth Medical School, Hanover, NH
03755, Department of Physiology, Johns Hopkins University School of
Medicine, Baltimore, MD 21205, Department of Physiology, Michigan
State University, East Lansing, MI 48824
APStracts 2:0116C, 1995.
McCoy, David E., Erik M. Schwiebert, Katherine H. Karlson, William S.
Spielman and Bruce A. Stanton. Identification and function of A1
adenosine receptors in normal and cystic fibrosis human airway
epithelial cells. A role for adenosine in the regulation of ion
transport in pulmonary epithelial cells has recently been proposed.
Although evidence exists documenting the presence and function of
adenosine A2 receptors in airway epithelia, the presence of adenosine
A1 receptors in airway epithelia remains controversial. The present
study used reverse transcriptase-polymerase chain reaction (RT-PCR)
and whole cell patch-clamp analysis to investigate A1 receptor
presence and function in normal and cystic fibrosis (CF) human airway
epithelial cells. Oligonucleotide primers complimentary to the human
brain A1 receptor sequence generated a PCR product of the predicted
size (311 bp) in normal tracheal (9HTEo-) and CF submucosal (2CFSMEo
-) airway cell lines and in primary cultures of CF nasal polyp
epithelial cells. An oligonucleotide probe internal to the PCR
primers hybridized with the 311 bp cDNAs by Southern blot analysis.
cDNA sequencing demonstrated that the normal and CF airway cell PCR
products are 100% identical to the corresponding sequence of the
human brain adenosine A1 receptor. Northern blot analysis of 9HTEo-
and 2CFSMEo- poly(A+) RNA revealed the presence of two bands of 3.0
kB and 5.5 kB corresponding to the A1 receptor. Whole cell patch
-clamp analyses demonstrated that DPCPX, a specific A1 receptor
antagonist, increases cAMP-activated Cl- conductance in 9HTEo- airway
cells and allows cAMP to increase Cl- conductance in 2CFSMEo- CF
airway cells and CF nasal polyp epithelial cells in primary culture.
These results provide evidence for the presence and function of A1
receptors in normal and CF airway epithelial cells and provide
support for a role of adenosine A1 receptors in modulating airway
epithelial cell Cl- transport.
Received 15 August 1994; accepted in final form 20 December 1994.
APS Manuscript Number C485-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 7 March 1995.