Premium
The Extracellular Calcium‐Sensing Receptor Is Expressed in Rat Microglia and Modulates an Outward K + Channel
Author(s) -
Chattopadhyay Naibedya,
Ye Chianping,
Yamaguchi Toru,
Nakai Masamichi,
Kifor Olga,
Vassilev Peter M.,
Nishimura Robert N.,
Brown Edward M.
Publication year - 1999
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1046/j.1471-4159.1999.0721915.x
Subject(s) - extracellular , microglia , neuroscience , calcium sensing receptor , calcium , chemistry , receptor , channel (broadcasting) , biophysics , microbiology and biotechnology , medicine , endocrinology , biology , biochemistry , computer science , calcium metabolism , inflammation , telecommunications
The calcium‐sensing receptor (CaR) is a G protein‐coupled receptor that “senses” extracellular calcium ions (Ca 2+ o) as an extracellular first messenger. In this report, we have shown that the CaR is expressed in primary cultures of microglial cells derived from rat brain as assessed by RT‐PCR using four CaR‐specific primer pairs followed by sequencing of the amplified products, by northern blot analysis using a CaR‐specific probe, as well as by immunocytochemistry and western analysis utilizing a specific polyclonal anti‐CaR antiserum. In addition, raising Ca 2+ , from 0.75 to 3.0 mM or addition of the polycationic CaR agonist neomycin or a “calcimimetic” CaR activator (R‐467; NPS Pharmaceuticals) increased the open state probability (Po) of a Ca + ‐activated Kf channel having a unitary conductance of 84 ± 4 pS, indicating that the channel is modulated by the CaR. Therefore, our data strongly suggest that a functional CaR is expressed in cultured rat microglia, similar to that in parathyroid gland and kidney, which could potentially play an important role(s) in regulating microglial function.