Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2006-1-23
pubmed:abstractText
Ion channels, such as the epithelial sodium channel (ENaC), are essential for maintaining a fluid-free middle ear cavity by controlling periciliary fluid. Deviations from the normal volume or compositions of periciliary fluid are probably responsible for otitis media with effusion. To elucidate the physiologic roles of the ENaC and cystic fibrosis transmembrane conductance regulator (CFTR) in the middle ear mucosa, we compared the electrophysiological activity and protein expressions of ENaC and CFTR in normal human middle ear epithelial (NHMEE) cells with those in normal human nasal epithelial (NHNE) cells. We also evaluated the role of ENaC and CFTR in fluid transport by NHMEE cells. Short-circuit current (Isc) was measured in cell monolayers by modified Ussing chambers. Immunoblotting was performed for ENaC and CFTR. In addition, transepithelial fluid transport was measured after loading 100 microl of fluid onto the luminal cell surface. The amiloride-sensitive Isc in NHMEE cells was much larger than in NHNE cells, whereas the forskolin-induced Isc, presumably mediated by CFTR, was significantly smaller in NHMEE cells. ENaC subunits alpha, beta, and gamma were all detected in NHMEE cells, and their expressions were stronger than those in NHNE cells. In comparison, CFTR was also detected in the middle ear mucosa, but at a lower expression level than in NHNE cells. NHMEE cells showed more amiloride-sensitive fluid absorption than NHNE cells. In contrast, fluid absorption was less sensitive to forskolin/IBMX in NHMEE cells than in NHNE cells. The ATP induced Cl- efflux and the amplitude of ATP-induced current in NHMEE cells was much larger than in NHNE cells. In the present study, we have demonstrated an enhanced amiloride-sensitive Isc and fluid absorption in NHMEE cells, where the role of CFTR is limited. Our data also suggest that the ATP-induced Cl- channel could be an alternative Cl- channel to CFTR in NHMEE cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/1-Methyl-3-isobutylxanthine, http://linkedlifedata.com/resource/pubmed/chemical/4,4'-Diisothiocyanostilbene-2,2'-Dis..., http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate, http://linkedlifedata.com/resource/pubmed/chemical/Amiloride, http://linkedlifedata.com/resource/pubmed/chemical/CFTR protein, human, http://linkedlifedata.com/resource/pubmed/chemical/CLCA1 protein, human, http://linkedlifedata.com/resource/pubmed/chemical/Chloride Channels, http://linkedlifedata.com/resource/pubmed/chemical/Cystic Fibrosis Transmembrane..., http://linkedlifedata.com/resource/pubmed/chemical/Epithelial Sodium Channel, http://linkedlifedata.com/resource/pubmed/chemical/Forskolin, http://linkedlifedata.com/resource/pubmed/chemical/Sodium Channels
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0378-5955
pubmed:author
pubmed:issnType
Print
pubmed:volume
211
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
26-32
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:16226002-1-Methyl-3-isobutylxanthine, pubmed-meshheading:16226002-4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid, pubmed-meshheading:16226002-Adenosine Triphosphate, pubmed-meshheading:16226002-Amiloride, pubmed-meshheading:16226002-Cells, Cultured, pubmed-meshheading:16226002-Chloride Channels, pubmed-meshheading:16226002-Cystic Fibrosis Transmembrane Conductance Regulator, pubmed-meshheading:16226002-Ear, Middle, pubmed-meshheading:16226002-Epithelial Cells, pubmed-meshheading:16226002-Epithelial Sodium Channel, pubmed-meshheading:16226002-Forskolin, pubmed-meshheading:16226002-Humans, pubmed-meshheading:16226002-Ion Transport, pubmed-meshheading:16226002-Nasal Mucosa, pubmed-meshheading:16226002-Sodium Channels, pubmed-meshheading:16226002-Water-Electrolyte Balance
pubmed:year
2006
pubmed:articleTitle
ENaC- and CFTR-dependent ion and fluid transport in human middle ear epithelial cells.
pubmed:affiliation
Department of Otorhinolaryngology, Yonsei University College of Medicine, 134 Shinchon-dong, Seodaemun-gu Seoul, 120-752, Republic of Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't