Basile A S, Klein D C, Skolnick P
Brain Res. 1986 Nov;387(2):127-35. doi: 10.1016/0169-328x(86)90004-5.
Bovine and rat pineal benzodiazepine receptors were characterized using ligands with high affinities for either 'central-type' (CBR) or 'peripheral-type' (PBR) benzodiazepine receptors. The characteristics (Bmax = 83 +/- 10 fmol/mg protein, Kd = 3.88 +/- 0.46 nM) of benzodiazepine receptors in bovine pineal membranes measured with [3H]flunitrazepam (using flunitrazepam to define non-specific binding) were consistent with previously reported values. However, if non-specific binding was defined using Ro 15-1788 (a selective CBR ligand), the Bmax and Kd of [3H]flunitrazepam decreased 51 and 58%, respectively. In addition, when using PK 11195 to determine non-specific binding, the Bmax of [3H]flunitrazepam binding to bovine pineal decreased further (approximately 80%, Kd decreased approximately 39%). Together, these observations strongly suggested the presence of PBR in the bovine pineal. Bovine pineal PBR characterized with [3H]PK 11195 revealed a high density (relative to CBR) of high affinity binding sites (Kd = 1.08 +/- 0.30, Bmax = 776 +/- 33.0 fmol/mg protein). In contrast, when [3H]Ro 5-4864 (1-20 nM) was used to define PBR, no binding was detectable. These observations are in sharp contrast to the rat pineal gland, in which both [3H]Ro 5-4864 and [3H]PK 11195 bind to a large number of PBR with high affinity (Kd approximately equal to 1.9 nM, Bmax approximately equal to 26 pmol/mg protein). Bovine pineal PBR were further characterized with compounds structurally related to either Ro 5-4864 or PK 11195.(ABSTRACT TRUNCATED AT 250 WORDS)
利用对“中枢型”（CBR）或“外周型”（PBR）苯二氮䓬受体具有高亲和力的配体，对牛和大鼠松果体的苯二氮䓬受体进行了表征。用[³H]氟硝西泮测定牛松果体膜中苯二氮䓬受体的特性（Bmax = 83 ± 10 fmol/mg蛋白，Kd = 3.88 ± 0.46 nM）（使用氟硝西泮定义非特异性结合）与先前报道的值一致。然而，如果使用Ro 15 - 1788（一种选择性CBR配体）定义非特异性结合，[³H]氟硝西泮的Bmax和Kd分别降低了51%和58%。此外，当使用PK 11195测定非特异性结合时，[³H]氟硝西泮与牛松果体结合的Bmax进一步降低（约80%），Kd降低约39%。这些观察结果强烈表明牛松果体中存在PBR。用[³H]PK 11195表征的牛松果体PBR显示出高密度（相对于CBR）的高亲和力结合位点（Kd = 1.08 ± 0.30，Bmax = 776 ± 33.0 fmol/mg蛋白）。相比之下，当使用[³H]Ro 5 - 4864（1 - 20 nM）定义PBR时，未检测到结合。这些观察结果与大鼠松果体形成鲜明对比，在大鼠松果体中，[³H]Ro 5 - 4864和[³H]PK 11195都以高亲和力（Kd约等于1.9 nM，Bmax约等于26 pmol/mg蛋白）与大量PBR结合。用与Ro 5 - 4864或PK 11195结构相关的化合物对牛松果体PBR进行了进一步表征。（摘要截短于250字）
