Linked Life Data

2315004

Source:http://linkedlifedata.com/resource/pubmed/id/2315004

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1990-4-13
pubmed:abstractText
The membrane electrical properties of undifferentiated pheochromocytoma cells of the rat (PC12) were studied using both current- and voltage-clamp techniques with the use of low-resistance blunt-tipped micropipettes (patch electrodes). In the presence of tetrodotoxin (TTX, 2-3 microM), a spike-like wave form with a prominent after-hyperpolarization (AHP) was recorded following brief (less than 10 ms) depolarizing current pulses. The inorganic divalent cations, Cd2+ (0.5 mM), Mn2+ (4 mM), and 0 mM Ca2+/4 mM Mg2+ solution prolonged the duration, attenuated the AHP, slowed the rate of repolarization, and slightly enhanced the amplitude of this wave form. A rapidly inactivating outward current was recorded in over 70% of the cells under voltage-clamp conditions. This transient current was elicited at about -30 mV, and was blocked by tetraethylammonium (5 mM), inorganic divalent cations (Cd2+, 0.5 mM; Mn2+, 4 mM; Ba2+, 3 mM), and removal of Ca2+ (0 mM Ca2+/4 mM Mg2+) from the local perfusion medium. In addition, 4-aminopyridine (5 mM), which blocks the transient outward K+ current IA in a variety of excitable cells, did not have any appreciable effect on this rapidly inactivating current. Moreover, it was possible to elicit the current at a holding potential of -40 mV. The reversal potential of this current was -90 mV, and shifted positively when extracellular K+ concentrations were elevated. It is concluded that PC12 cells have a rapidly inactivating Ca2(+)-dependent K+ current. A possible explanation for the transient nature of this current may be the presence of an effective intracellular Ca2+ buffering (uptake or extrusion) system.
pubmed:grant
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
415
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
425-32
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
A rapidly inactivating Ca2(+)-dependent K+ current in pheochromocytoma cells (PC12) of the rat.
pubmed:affiliation
Department of Physiology and Biophysics, University of Cincinnati, College of Medicine, OH 45267-0576.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.