Bonnet M, Lespinats G, Burtin C
Int J Immunopharmacol. 1987;9(5):551-8. doi: 10.1016/0192-0561(87)90122-6.
The binding of 3H-labeled serotonin (or 5-hydroxytryptamine: 5HT) to mouse lymphocytes was investigated. It was shown to be highly specific, time-dependent, saturable and partly reversible. Saturation analysis demonstrated a Kd of 198 nM and B max of 3.53 nM. We studied receptor specificity by using different types of serotonin antagonists, and numerous other substances. Serotonin was found to be the most effective drug among those tested in inhibiting the binding of 3H-5HT, having an IC50 of 194 nM. The fact that 5HTP, a 5HT precursor, had no inhibitory capacity indicated the high specificity of these 5HT binding sites. Dopamine was somewhat able to competitively inhibit 5HT fixation (IC50 = 27,000 nM), whereas norepinephrine and histamine had no effect. Lastly, we investigated the cellular specificity of this binding, and observed that nonmacrophage peritoneal cells extensively bound serotonin under the same conditions as spleen cells. This is the first direct demonstration of 5-hydroxytryptamine receptors on mouse lymphocytes. The presence of these binding sites can contribute to the understanding of the suppressive effect of 5HT on mouse immunoreactivity.
研究了3H标记的血清素（或5-羟色胺：5HT）与小鼠淋巴细胞的结合情况。结果表明这种结合具有高度特异性、时间依赖性、可饱和性且部分可逆。饱和分析显示解离常数（Kd）为198 nM，最大结合量（B max）为3.53 nM。我们通过使用不同类型的血清素拮抗剂和许多其他物质来研究受体特异性。在测试的药物中，血清素是抑制3H-5HT结合最有效的药物，其半数抑制浓度（IC50）为194 nM。5HT前体5-羟色氨酸（5HTP）没有抑制能力，这一事实表明这些5HT结合位点具有高度特异性。多巴胺能够部分竞争性抑制5HT的结合（IC50 = 27,000 nM），而去甲肾上腺素和组胺则没有作用。最后，我们研究了这种结合的细胞特异性，发现在与脾细胞相同的条件下，非巨噬细胞腹膜细胞能大量结合血清素。这是首次直接证明小鼠淋巴细胞上存在5-羟色胺受体。这些结合位点的存在有助于理解5HT对小鼠免疫反应的抑制作用。
