A subtype of nicotinic cholinergic receptor in rat brain is composed of alpha 4 and beta 2 subunits and is up-regulated by chronic nicotine treatment.
A subtype of nicotinic cholinergic receptor in rat brain is composed of alpha 4 and beta 2 subunits and is up-regulated by chronic nicotine treatment.
复制标题
DOI：
--
复制
发表时间：
1992
影响因子：
3.6
通讯作者：
Christopher M. Flores;Scott W. Rogers;L. Pabreza;B. Wolfe;K. Kellar
中科院分区：
文献类型：
--
作者：
Christopher M. Flores;Scott W. Rogers;L. Pabreza;B. Wolfe;K. Kellar
大鼠神经元烟碱胆碱能受体的亚基组成和药理学调节进行了评估。使用[3 H]金雀花碱，烟碱受体的高亲和力激动剂，与多克隆抗血清对包括这种受体类的各种亚基的非同源结构域产生的溶解的大鼠脑匀浆中确定特异性免疫沉淀。在所有测试的大脑区域中，只有针对α 4和β 2亚基产生的抗血清能够免疫沉淀[3 H]野靛碱特异性标记的受体。因此，进一步表征这些血清以验证和优化其在免疫沉淀方案中的用途。用抗α 2、α 3、α 5、β 3或β 4亚基产生的抗血清预孵育大鼠前脑可溶性受体，未降低可沉淀α 4或β 2亚基的量。另一方面，当使用抗α 4或抗β 2血清免疫沉淀来自大鼠前脑的溶解受体时，上清液几乎不含可由任一抗体特异性沉淀的任何剩余受体。由于这些抗血清不交叉反应，数据表明，α 4和β 2亚基在至少一种对激动剂具有高亲和力的神经元烟碱受体亚型中彼此相关。此外，这些结果意味着所有被[3 H]胱氨酸标记的α 4亚基都与β 2亚基偶联。我们还提供了证据表明，本报告中描述的α 4/β 2亚型在长期接受尼古丁治疗的大鼠皮质中显著增加。
The subunit composition and pharmacological regulation of rat neuronal nicotinic cholinergic receptors were assessed. Specific immunoprecipitation was determined in solubilized rat brain homogenates using [3H]cytisine, a high affinity agonist at nicotinic receptors, in conjunction with polyclonal antisera generated against nonhomologous domains of the various subunits comprising this receptor class. In all brain regions tested, only antisera generated against the alpha 4 and beta 2 subunits were able to immunoprecipitate specifically receptors labeled by [3H]cytisine. Thus, these sera were further characterized in order to validate and optimize their use in the immunoprecipitation protocol. Preincubation of solubilized receptors from rat forebrain with antisera generated against the alpha 2, alpha 3, alpha 5, beta 3, or beta 4 subunits did not decrease the amount of precipitable alpha 4 or beta 2 subunit. On the other hand, when either anti-alpha 4 or anti-beta 2 serum was used to immunoprecipitate solubilized receptors from rat forebrain, the supernatants contained little if any remaining receptors that could be specifically precipitated by either antibody. Because these antisera do not cross-react, the data indicate that alpha 4 and beta 2 subunits are associated with each other in at least one neuronal nicotinic receptor subtype that has high affinity for agonists. Moreover, these results imply that all alpha 4 subunits that are labeled by [3H]cystisine are coupled to beta 2 subunits. We also present evidence that the alpha 4/beta 2 subtype characterized in this report is significantly increased in the cortex of rats chronically treated with nicotine.