Minneman K P, Mowry C B
Biochem Pharmacol. 1986 Mar 1;35(5):857-64. doi: 10.1016/0006-2952(86)90255-8.
Three compounds that have been suggested to irreversibly inactivate beta-adrenergic receptors were studied: NHNPNBE [N-(2-hydroxy-3-[1-napthoxy]-propyl)-N-bromoacetylethylenediami ne], BAAM (bromoacetylalprenololmenthane), and Ro 3-7894 [1-(5-chloracetylaminobenzfuran-2-yl)-2-isopropylaminoethanol++ +]. Membranes of rat cerebral cortex were used as a source of predominantly beta 1-adrenergic receptors and membranes of rat cerebellum were used as a source of predominantly beta 2-adrenergic receptors. Beta-Adrenergic receptor binding sites were studied by Scatchard analysis of saturation isotherms of specific [125I]-pindolol ([125I]PIN) binding. NHNPNBE added to the incubation medium competitively inhibited specific [125I]PIN binding in both cerebellum and cerebral cortex with KI values of 1-2 microM in each tissue. After washout of membranes pretreated with NHNPNBE for 30 min at 37 degrees, no loss of specific [125I]PIN binding sites was observed in either cerebellum or cortex except at very high concentrations (30-100 microM). Ro 3-7894 caused a simple competitive inhibition of specific [125I]PIN binding in rat cerebellar membranes with a KI of approximately 14 microM, an effect which was reversed completely by washing. In cerebral cortex, Ro 3-7894 added to the incubation medium apparently decreased the density of [125I]PIN binding sites with an IC50 around 1 microM. This effect was reversed after washing the membranes twice. However, in the presence of Ro 3-7894 some Scatchard plots showed a slight curvature. Further saturation of the [125I]PIN binding sites in cerebral cortex showed that the inhibition by Ro 3-7894 was competitive but with a high- and low-affinity component, consistent with Ro 3-7894 being a beta 1-selective competitive antagonist. Ro 3-7894 was also beta 1-selective in other tissues. BAAM added to the incubation medium competitively inhibited specific [125I]PIN binding in both cerebellum and cortex with KI values of 0.006 to 0.03 microM, but was about 5-fold more potent in cerebellum. After treatment of membranes with higher concentrations of BAAM for 30 min at 37 degrees and washing twice, there was a dose-dependent decrease in the density of specific [125I]PIN binding sites with IC50 values of approximately 0.3 microM in both tissues. Similar effects were observed in rat heart. These data suggest that NHNPNBE is a simple competitive antagonist at both beta 1- and beta 2-adrenergic receptors except at very high concentrations. Ro 3-7894 is a beta 1-selective competitive antagonist with no apparent irreversible effects.(ABSTRACT TRUNCATED AT 400 WORDS)
对三种曾被认为可使β - 肾上腺素能受体不可逆失活的化合物进行了研究：NHNPNBE [N - (2 - 羟基 - 3 - [1 - 萘氧基] - 丙基) - N - 溴乙酰乙二胺]、BAAM（溴乙酰阿普洛尔薄荷烷）和Ro 3 - 7894 [1 - (5 - 氯乙酰氨基苯并呋喃 - 2 - 基) - 2 - 异丙氨基乙醇]。大鼠大脑皮质膜用作主要含β1 - 肾上腺素能受体的来源，大鼠小脑膜用作主要含β2 - 肾上腺素能受体的来源。通过对特异性[125I] - 吲哚洛尔（[125I]PIN）结合饱和等温线进行Scatchard分析来研究β - 肾上腺素能受体结合位点。添加到孵育培养基中的NHNPNBE在小脑和大脑皮质中均竞争性抑制特异性[125I]PIN结合，每个组织中的抑制常数（KI）值为1 - 2微摩尔。在用NHNPNBE在37℃预处理30分钟后冲洗膜，除了在非常高的浓度（30 - 100微摩尔）下，在小脑或皮质中均未观察到特异性[125I]PIN结合位点的损失。Ro 3 - 7894在大鼠小脑膜中引起特异性[125I]PIN结合的简单竞争性抑制，抑制常数（KI）约为14微摩尔，这种作用通过冲洗可完全逆转。在大脑皮质中，添加到孵育培养基中的Ro 3 - 7894明显降低[125I]PIN结合位点的密度，半数抑制浓度（IC50）约为1微摩尔。在冲洗膜两次后这种作用逆转。然而，在存在Ro 3 - 7894的情况下，一些Scatchard图显示出轻微的曲率。大脑皮质中[125I]PIN结合位点的进一步饱和表明，Ro 3 - 7894的抑制作用是竞争性的，但具有高亲和力和低亲和力成分，这与Ro 3 - 7894是一种β1选择性竞争性拮抗剂一致。Ro 3 - 7894在其他组织中也是β1选择性的。添加到孵育培养基中的BAAM在小脑和皮质中均竞争性抑制特异性[125I]PIN结合，抑制常数（KI）值为0.006至0.03微摩尔，但在小脑中的效力约高5倍。在用较高浓度的BAAM在37℃处理膜30分钟并冲洗两次后，两个组织中特异性[125I]PIN结合位点的密度呈剂量依赖性降低，半数抑制浓度（IC50）值约为0.3微摩尔。在大鼠心脏中也观察到类似的作用。这些数据表明，除了在非常高的浓度下，NHNPNBE在β1和β2肾上腺素能受体上均为简单的竞争性拮抗剂。Ro 3 - 7894是一种β1选择性竞争性拮抗剂，无明显的不可逆作用。（摘要截短为400字）
