Linked Life Data

8146026

Source:http://linkedlifedata.com/resource/pubmed/id/8146026

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
1994-5-3
pubmed:abstractText
There is ample evidence that retinal radial glial (Müller) cells play a crucial role in retinal ion homeostasis. Nevertheless, data on the particular types of ion channels mediating this function are very rare and incomplete; this holds especially for mammalian Müller cells. Thus, the whole-cell variation of the patch-clamp technique was used to study voltage-dependent currents in Müller cells from adult rabbit retinae. The membrane of Müller cells was almost exclusively permeable to K+ ions, as no significant currents could be evoked in K(+)-free internal and external solutions, external Ba2+ (1 mM) reversibly blocked most membrane currents, and external Cs+ ions (5 mM) blocked all inward currents. All cells expressed inwardly rectifying channels that showed inactivation at strong hyperpolarizing voltages (> or = -120 mV), and the conductance of which varied with the square root of extracellular K+ concentration ([K+]e). Most cells responded to depolarizing voltages (> or = -30 mV) with slowly activating outward currents through delayed rectifier channels. These currents were reversibly blocked by external application of 4-aminopyridine (4-AP, 0.5 mM) or tetraethylammonium (TEA, > 20 mM). Additionally, almost all cells showed rapidly inactivating currents in response to depolarizing (> or = -60 mV) voltage steps. The currents were blocked by Ba2+ (1 mM), and their amplitude increased with the [K+]e. Obviously, these currents belonged to the A-type family of K+ channels. Some of the observed types of K+ channels may contribute to retinal K+ clearance but at least some of them may also be involved in regulation of proliferative activity of the cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
426
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
51-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Three distinct types of voltage-dependent K+ channels are expressed by Müller (glial) cells of the rabbit retina.
pubmed:affiliation
Carl Ludwig Institute of Physiology, Department of Cellular Neurobiology, Leipzig University, Germany.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't