Differences in G-protein activation by mu- and delta-opioid, and cannabinoid, receptors in rat striatum.
Differences in G-protein activation by mu- and delta-opioid, and cannabinoid, receptors in rat striatum.
复制标题
大鼠纹状体中 mu- 和 delta-阿片类药物以及大麻素受体激活 G 蛋白的差异。
DOI：
10.1016/0014-2999(96)00211-7
复制
发表时间：
1996
影响因子：
5
通讯作者：
Childers,SR
中科院分区：
文献类型：
--
作者：
Sim,LJ;Selley,DE;Xiao,R;Childers,SR
G 蛋白的受体激活可以通过在存在过量二磷酸鸟苷 (GDP) 的情况下激动剂刺激的 [35S]GTPγS 结合来测量。为了确定阿片类药物和大麻素受体介导的 G 蛋白激活是否与其受体密度相关，本研究比较了阿片类药物和大麻素刺激的 [35S]鸟苷基-5'-O-(γ-硫代)-三磷酸 (GTPγS) 结合与大鼠纹状体中受体结合的相应 Bmax 值。 Scatchard 分析表明，大麻素受体结合的 Bmax 大约比 μ- 或 δ-阿片受体结合高十倍。然而，通过脑切片中的[35S]GTPγS放射自显影，在尾壳核中观察到大麻素、μ-和δ-阿片类刺激的[35S]GTPγS结合水平相当。 Scatchard 对膜中净激动剂刺激的 [35S]GTPγS 结合的分析表明，大麻素刺激的结合的 Bmax 仅是 μ- 或 δ-阿片类药物刺激的结合的两倍。因此，计算出的μ-和δ-阿片受体的放大因子是大麻素受体的七倍。
Receptor activation of G-proteins can be measured by agonist-stimulated [35S]GTPγS binding in the presence of excess guanosine diphosphate (GDP). To determine whether opioid and cannabinoid receptor-mediated G-protein activation correlate with their receptor densities, this study compared opioid- and cannabinoid-stimulated [35S]guanylyl-5′-O-(γ-thio)-triphosphate (GTPγS) binding with the corresponding Bmaxvalues of receptor binding in rat striatum. Scatchard analysis revealed that the Bmaxof cannabinoid receptor binding was approximately ten times higher than that of μ- or δ-opioid receptor binding. However, comparable levels of cannabinoid- and μ- and δ-opioid-stimulated [35S]GTPγS binding were observed in the caudate-putamen by [35S]GTPγS autoradiography in brain sections. Scatchard analysis of net agonist-stimulated [35S]GTPγS binding in membranes showed that the Bmaxof cannabinoid-stimulated binding was only twice that of μ- or δ-opioid-stimulated binding. Thus, the calculated amplification factors for μ- and δ-opioid receptors are seven times that of cannabinoid receptors.