Linked Life Data

8534793

Source:http://linkedlifedata.com/resource/pubmed/id/8534793

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1996-2-6
pubmed:abstractText
When placed at the tip of a glass micropipette electrode the polymeric matrix of the secretory granule behaves like a diode. The measured current was 100-fold greater at negative potentials compared to positive potentials, and up to sixfold greater than that measured with the pipette alone. By manipulating the geometry of the electric field we show that these electrical properties result from focusing an electric field at the gel-electrolyte interface. We also show, by using pulsed-laser imaging with fluorescein as the ionic probe, that there is a rapid accumulation and depletion of ions at the gel-electrolyte interface. A voltage pulse of -9 V applied to the gel caused a severalfold increase in the fluorescence intensity within 5 ms. This correlated with an increase in the measured current (approximately 1 microA). In contrast, within 5 ms of applying +9 V we recorded a decrease in the fluorescence intensity, which paralleled the twofold decrease in the measured current. This is similar to a p-n junction where an applied voltage causes the accumulation and depletion of charge carriers. Using synthetic gels (diameter 3-6 microns) with different charge characteristics we observed no rectification of the current with neutral gels and confirmed that rectification and amplification of the current were dependent on the fixed charge within a gel. In addition, we modeled the conduction at the gel-electrolyte interface using the Nernst-Planck electrodiffusion equation and accurately fitted the experimental current-voltage relationships. This study provides some insight into how biological interfaces may function. For example, we suggest that neurotransmitter release during exocytosis could be regulated by voltage-induced accumulation and depletion of ions at the interface between the secretory granule and the fusion pore.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1377642, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1420930, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1549173, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1549182, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1730775, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-17808541, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1868152, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-1956379, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-2015389, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-2442614, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-3816417, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-7195985, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-7209484, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-7909233, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-7948669, http://linkedlifedata.com/resource/pubmed/commentcorrection/8534793-8438154
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1218-29
pubmed:dateRevised
2010-9-13
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The secretory granule matrix-electrolyte interface: a homologue of the p-n rectifying junction.
pubmed:affiliation
Department of Physiology and Biophysics, Mayo Clinic, Rochester, MN 55905, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't