Ricci A, Bronzetti E, Felici L, Tayebati S K, Amenta F
Dipartimento di Scienze Cardiovascolari e Respiratorie, Università La Sapienza, Rome, Italy.
Neurosci Lett. 1997 Jun 27;229(2):130-4. doi: 10.1016/s0304-3940(97)00413-8.
The expression of dopamine D4 receptor was investigated in human peripheral blood lymphocytes with a radioligand binding assay technique, using [3H]clozapine as radioligand. [3H]Clozapine was specifically bound to human peripheral blood lymphocytes. The binding was time-, temperature-, and concentration-dependent and of high affinity, with a dissociation constant (K(d)) value of 0.34 +/- 0.02 nM and a maximum density of binding sites (B(max)) value of 27 +/- 1.4 fmol/10(6) cells. The pharmacological profile of [3H]clozapine binding to human peripheral blood lymphocytes was similar to that found in Chinese hamster ovary (CHO) cells transfected with the D4 clone (D4.2 variant). The above results are consistent with molecular biology studies demonstrating the expression of a dopamine D4 receptor in immune cells and in human peripheral blood lymphocytes. The availability of a rapid and sensitive radioligand binding assay technique for the dopamine D4 receptor in human peripheral blood lymphocytes may contribute to better define the role of this dopamine receptor subtype in neurological and psychiatric disorders.
采用放射性配体结合分析技术，以[3H]氯氮平作为放射性配体，研究了多巴胺D4受体在人外周血淋巴细胞中的表达。[3H]氯氮平与人外周血淋巴细胞特异性结合。这种结合具有时间、温度和浓度依赖性，且亲和力高，解离常数（K(d)）值为0.34±0.02 nM，最大结合位点密度（B(max)）值为27±1.4 fmol/10(6)个细胞。[3H]氯氮平与人外周血淋巴细胞结合的药理学特征与转染了D4克隆（D4.2变体）的中国仓鼠卵巢（CHO）细胞中的情况相似。上述结果与分子生物学研究一致，该研究表明多巴胺D4受体在免疫细胞和人外周血淋巴细胞中表达。一种用于人外周血淋巴细胞中多巴胺D4受体的快速灵敏的放射性配体结合分析技术的可用性，可能有助于更好地确定这种多巴胺受体亚型在神经和精神疾病中的作用。
