Persistent Na+ influx drives L-type channel resting Ca2+ entry in rat melanotrophs
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11140%2F19%3A10399939" target="_blank" >RIV/00216208:11140/19:10399939 - isvavai.cz</a>
Result on the web
<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=q0TsewkboA" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=q0TsewkboA</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1016/j.ceca.2019.02.001" target="_blank" >10.1016/j.ceca.2019.02.001</a>
Alternative languages
Result language
angličtina
Original language name
Persistent Na+ influx drives L-type channel resting Ca2+ entry in rat melanotrophs
Original language description
Rat melanotrophs express several types of voltage-gated and ligand-gated calcium channels, although mechanisms involved in the maintenance of the resting intracellular Ca2+ concentration ([Ca2+](i)) remain unknown. We analyzed mechanisms regulating resting [Ca2+](i) in dissociated rat melanotrophs by Ca2+-imaging and patch-clamp techniques. Treatment with antagonists of L-type, but not N- or P/Q-type voltage-gated Ca2+ channels (VGCCs) as well as removal of extracellular Ca2+ resulted in a rapid and reversible decrease in [Ca2+](i), indicating constitutive Ca2+ influx through L-type VGCCs. Reduction of extracellular Na+ concentration (replacement with NMDG(+)) similarly decreased resting [Ca2+](i). When cells were champed at -80 mV, decrease in the extracellular Na+ resulted in a positive shift of the holding current. In cell-attached voltage-clamp and whole-cell current-clamp configurations, the reduction of extracellular Na+ caused hyperpolarisation. The holding current shifted in negative direction when extracellular K+ concentration was increased from 5 mM to 50 mM in the presence of K+ channel blockers, Ba2+ and TEA, indicating cation nature of persistent conductance. RT-PCR analyses of pars intermedia tissues detected mRNAs of TRPV1, TRPV4, TRPC6, and TRPM3-5. The TRPV channel blocker, ruthenium red, shifted the holding current in positive direction, and significantly decreased the resting [Ca2+](i). These results indicate operation of a constitutive cation conductance sensitive to ruthenium red, which regulates resting membrane potential and [Ca2+](i) in rat melanotrophs.
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
30104 - Pharmacology and pharmacy
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Cell Calcium
ISSN
0143-4160
e-ISSN
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Volume of the periodical
79
Issue of the periodical within the volume
May
Country of publishing house
GB - UNITED KINGDOM
Number of pages
9
Pages from-to
11-19
UT code for WoS article
000463866200002
EID of the result in the Scopus database
2-s2.0-85061453092