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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1-2
|
| pubmed:dateCreated |
1990-9-5
|
| pubmed:abstractText |
The patch-clamp technique was utilized to characterize a cation channel in peptidergic nerve terminals isolated from a crustacean neurosecretory system. The cation channel exhibits the unique property of being activated by [Na+]. Distributions of open times demonstrate the presence of two open states with a shift of the distribution from predominantly short open times at [Na+] less than or equal to 10 mM to a predominantly long open state at [Na+] greater than or equal to 40 mM. Desensitization of channel activation occurs on prolonged exposure to [Na+] greater than 40 mM. Open probability increased steeply with [Na+] but was largely independent of membrane potential. Comparison of current-voltage relationships from single dissociated terminals and from those in the intact system show no differences in conductance or selectivity with nearly equal permeability to Na+ and K+, and impermeability to Cs+, divalent cations and anions. Flickering block occurred with [Ca2+]i greater than 1 microM. We propose that Na-activated cation (NAC) channels are activated by Na+ entering during action potentials and provide a sustained depolarizing current that can help sustain repetitive or bursting activity and subsequent facilitation of secretion from these nerve terminals.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
May
|
| pubmed:issn |
0006-8993
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
28
|
| pubmed:volume |
517
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
35-43
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading | |
| pubmed:year |
1990
|
| pubmed:articleTitle |
Sodium-activated cation channels in peptidergic nerve terminals.
|
| pubmed:affiliation |
Békésy Laboratory of Neurobiology, University of Hawaii, Honolulu 96822.
|
| pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
|