3H-Spiperone labels sigma receptors, not dopamine D2 receptors, in rat and human lymphocytes.
Coccini-T; Manzo-L; Costa-LG
Immunopharmacology 1991 Sep-Oct; 22(2):93-105
The characteristics of the binding of tritium (H3) labeled spiperone (749020) in lymphocytes was investigated, as part of a larger study aimed at exploring the potential use of neurotransmitter receptors in circulating blood cell as markers for the same receptors in solid tissues. Adult male Sprague-Dawley-rat spleen lymphocytes or human blood lymphocytes were used in binding assays. The findings suggested that H3 labeled spiperone binds to a high affinity, saturable site in rat and human lymphocytes. The binding was similar at either 37 or 4 degrees-C, suggesting that the observed binding was not due to nonspecific trapping of H3 labeled spiperone into the cell or to a specific uptake system. The binding was saturable in a range of concentrations between 0.5 and 50 nanomolar; however, the dissociation constant was about 40 fold higher than that of H3 labeled spiperone in striatum. The authors conclude that H3 labeled spiperone labels a population of sites in rat and human lymphocytes which can be better characterized as sigma receptors rather than dopamine D2 receptors. These findings also suggest that changes in H3 labeled spiperone binding observed in lymphocytes from schizophrenic patients may represent changes in sigma receptors in these cells.
NIOSH-Publication; NIOSH-Grant; Neurotoxic-effects; Laboratory-animals; Blood-cells; In-vitro-studies
Environmental Health University of Washington Dept/environmental Hlth/sc-34 Seattle, WA 98195
Neurotoxic Disorders; Neurotoxic-effects
University of Washington, Seattle, Washington