Molecular evidence for a glycine-gated chloride channel in macrophages and leukocytes.
Recent studies have demonstrated that glycine blunts the response of Kupffer cells to endotoxin. Based on pharmacological evidence, it was hypothesized that Kupffer cells and other macrophages contain a glycine-gated chloride channel similar to the glycine receptor expressed in neuronal tissues. Moreover, glycine stimulates influx of radiolabeled chloride in Kupffer cells in a dose-dependent manner. RT-PCR was used to identify mRNA of both alpha- and beta-subunits of the glycine receptor in rat Kupffer cells, peritoneal neutrophils, and splenic and alveolar macrophages, similar to the sequence generated from rat spinal cord. Importantly, the sequence of the cloned Kupffer cell glycine receptor fragment for the beta-subunit was >95% homologous with the receptor from the spinal cord. Membranes of these cells also contain a protein that is immunoreactive with antibodies against the glycine-gated chloride channel. These data demonstrate that Kupffer cells, as well as other macrophages and leukocytes, express mRNA and protein for a glycine-gated chloride channel with both molecular and pharmacological properties similar to the channel expressed in the central nervous system.
Froh
Matthias
M
Laboratory of Hepatobiology and Toxicology, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7365, USA.
Thurman
Ronald G
RG
Wheeler
Michael D
MD
D000818:Animals; D000906:Antibodies / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D018118:Chloride Channels / Q000032:analysis* / Q000276:immunology / Q000502:physiology*; D002712:Chlorides / Q000378:metabolism; D005998:Glycine / Q000494:pharmacology*; D015640:Ion Channel Gating / Q000187:drug effects*; D007553:Isotope Labeling; D007728:Kupffer Cells / Q000737:chemistry / Q000378:metabolism; D007962:Leukocytes / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008264:Macrophages / Q000737:chemistry* / Q000378:metabolism; D016676:Macrophages, Alveolar / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008565:Membrane Proteins / Q000276:immunology; D009504:Neutrophils / Q000737:chemistry / Q000378:metabolism; D010537:Peritoneum / Q000166:cytology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D018009:Receptors, Glycine / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000166:cytology
D000906:Antibodies; D018118:Chloride Channels; D002712:Chlorides; C501174:Glra2 protein, rat; C491948:Glrb protein, rat; D008070:Lipopolysaccharides; D008565:Membrane Proteins; D012333:RNA, Messenger; D018009:Receptors, Glycine; C408089:glycine receptor, alpha4-subunit; D002118:Calcium; D005998:Glycine