PubMed Journals: Am J Physiol

  Source:		PMID: 7515578

    		Am J Physiol. 1994 May;266(5 Pt 1):L493-501.
			Calu-3: a human airway epithelial cell line
			that shows cAMP-dependent Cl- secretion.

			Shen BQ(1), Finkbeiner WE, Wine JJ, Mrsny
			RJ, Widdicombe JH.

			Author Information
			(1) Department of Physiology,
			University of California, San Francisco

			Of 12 cell lines derived from human lung
			cancers, only Calu-3 cells showed high
			transepithelial resistance (Rte) and increases
			in short-circuit current (Isc) in response
			to mediators. Calu-3 cells formed polarized
			monolayers with tight junctions and Rte
			of approximately 100 omega.cm2. Baseline
			Isc was approximately 35 microA/cm2 and
			was increased by approximately 75 microA/cm2
			on elevation of intracellular adenosine
			3',5'-cyclic monophosphate (cAMP) by isoproterenol.
			Flux studies showed that the increase in
			Isc was due to Cl- secretion. Forskolin
			and permeant analogues of cAMP also increased
			Isc. Consistent with the presence of cAMP-dependent
			Cl- secretion, immunoprecipitation demonstrated
			the presence of the cystic fibrosis transmembrane
			conductance regulator (CFTR). Bradykinin,
			methacholine, trypsin, and histamine all
			transiently (15-30 s) elevated Isc, probably
			by increasing intracellular Ca concentration.
			Experiments in which the basolateral membrane
			was permeabilized with nystatin indicated
			that CFTR was substantially activated under
			baseline conditions and that Ca-activated
			Cl- channels were absent from the apical
			membrane. We anticipate that Calu-3 cells
			will prove useful in the study of Cl- secretion
			and other functions of human airway epithelial

			DOI: 10.1152/ajplung.1994.266.5.L493 PMID: 7515578
			[Indexed for MEDLINE]

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