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 - and ß-subunits of the glycine receptor in rat Kupffer cells, peritoneal neutrophils, 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 b-subunit was >95% homologous with the receptor from spinal cord. The membranes of these cells also contain a protein which 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.