Cone R I, Rosenfeld S, Lameh J, Sadée W
Department of Pharmacy, University of California, San Francisco 94143-0446.
Life Sci. 1992;51(22):PL219-24. doi: 10.1016/0024-3205(92)90306-a.
The mouse neuroblastoma x rat glioma hybrid NG108-15 was previously shown to express delta opioid receptors. Because neuroblastoma cells display different phenotypes and cloned cell lines are heterogenous, we studied the characteristics and distribution of human 125I-beta-endorphin (125I-beta E) binding sites in cultures of NG108-15 cells with the use of micro-autoradiography and light microscopy. 125I-beta E labeled delta sites in NG108-15 in the presence of the non-opioid blocking peptide, beta-endorphin (6-31) (beta E (6-31)). Silver grains resulting from 125I-beta E binding to the opioid sites occurred in diffuse patches over several cells, with preferential location in dense cell patches. Pretreatment of NG108-15 with the delta agonist DADLE, previously shown to decrease beta E binding to delta sites on intact cells, also reduced silver grain density; however, some cells located in dense cell clusters were resistant to substantial agonist induced loss of labeling. These results suggest that delta opioid binding has a heterogenous cellular distribution in NG108.
小鼠神经母细胞瘤与大鼠胶质瘤的杂交细胞系NG108 - 15先前已被证明可表达δ阿片受体。由于神经母细胞瘤细胞表现出不同的表型且克隆细胞系具有异质性，我们利用显微放射自显影术和光学显微镜研究了人125I-β-内啡肽（125I-βE）在NG108 - 15细胞培养物中的结合位点的特征和分布。在非阿片类阻断肽β-内啡肽（6 - 31）（βE（6 - 31））存在的情况下，125I-βE标记了NG108 - 15中的δ位点。125I-βE与阿片类位点结合产生的银颗粒出现在几个细胞上的弥漫性斑块中，优先位于密集的细胞斑块中。用δ激动剂DADLE预处理NG108 - 15，先前已证明该激动剂可减少βE与完整细胞上δ位点的结合，这也降低了银颗粒密度；然而，一些位于密集细胞簇中的细胞对激动剂诱导的大量标记丢失具有抗性。这些结果表明，δ阿片类结合在NG108中具有异质性细胞分布。
