Linked Life Data

8203485

Source:http://linkedlifedata.com/resource/pubmed/id/8203485

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1994-7-7
pubmed:abstractText
The solute and water transport properties of the bovine ciliary epithelium were studied using isolated pigmented (PE) and nonpigmented (NPE) cells. It was shown that these cells were functionally coupled by demonstrating dye diffusion between paired PE and NPE cells after microinjection of lucifer yellow. Electronic cell sizing was used to measure cell volume changes of isolated PE and NPE cells in suspension after anisosmotic perturbations and after transport inhibition under isosmotic conditions. The PE cells showed the presence of a regulatory volume increase when subjected to osmotic shrinkage with NaCl, whereas the NPE cells did not demonstrate a regulatory volume increase under these conditions. In contrast, the NPE cells exhibited a regulatory volume decrease when subjected to osmotic swelling, whereas the PE cells did not recover from swelling. The regulatory volume decrease in NPE cells was inhibited by increased bath K or pretreatment with quinine (1 mM). The presence of a bumetanide-sensitive mechanism capable of moving measurable amounts of solute and water, probably Na-K-2Cl cotransport, was demonstrated in the PE cells but absent in the NPE cells. Bumetanide produced a dose-dependent shrinkage of PE cells at concentrations as low as 1 microM. Isosmotically reducing bath Cl, Na, or K concentration caused a rapid shrinkage of PE cells that was bumetanide inhibitable. The asymmetry of transport properties in PE and NPE cells supports a functional syncytium model of aqueous humor formation (39) across the two layers of the ciliary epithelium wherein ion uptake from the blood is carried out by the PE cells and ion extrusion by the NPE cells. Gap-junction coupling between the cells allows the ions taken up by the PE cells to move into the NPE cells. Extrusion of Na by the Na-K pump across the aqueous facing (basolateral) membranes of the NPE cells, most likely accompanied by Cl, determines the formation of the aqueous humor.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1210-21
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:8203485-Animals, pubmed-meshheading:8203485-Biological Transport, pubmed-meshheading:8203485-Cattle, pubmed-meshheading:8203485-Cell Communication, pubmed-meshheading:8203485-Cell Separation, pubmed-meshheading:8203485-Cells, Cultured, pubmed-meshheading:8203485-Centrifugation, Density Gradient, pubmed-meshheading:8203485-Chlorides, pubmed-meshheading:8203485-Ciliary Body, pubmed-meshheading:8203485-Epithelial Cells, pubmed-meshheading:8203485-Epithelium, pubmed-meshheading:8203485-Fluorescent Dyes, pubmed-meshheading:8203485-Homeostasis, pubmed-meshheading:8203485-Intercellular Junctions, pubmed-meshheading:8203485-Isoquinolines, pubmed-meshheading:8203485-Kinetics, pubmed-meshheading:8203485-Models, Biological, pubmed-meshheading:8203485-Potassium, pubmed-meshheading:8203485-Povidone, pubmed-meshheading:8203485-Silicon Dioxide, pubmed-meshheading:8203485-Time Factors
pubmed:year
1994
pubmed:articleTitle
Ion transport asymmetry and functional coupling in bovine pigmented and nonpigmented ciliary epithelial cells.
pubmed:affiliation
Department of Medicine, Wadsworth Veterans Administration Hospital, Los Angeles, California.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.