Minneman K P, Pittman R N, Yeh H H, Woodward D J, Wolfe B B, Molinoff P B
Brain Res. 1981 Mar 23;209(1):25-34. doi: 10.1016/0006-8993(81)91169-0.
Although beta 2-adrenergic receptors predominate in adult rat cerebellum, a small number of beta 1-receptors are also present. To investigate the cellular localization of beta 1- and beta 2-adrenergic receptors, the effects of intermittent neonatal X-irradiation focused on the cerebellum were determined on the densities of the two subtypes of beta-adrenergic receptor. This treatment destroys the late-maturing cerebellar interneurons including the granule, basket and stellate cells. A 60--70% loss of cerebellar mass was observed in 2-, 6- and 12-week-old animals. The large early-maturing Purkinje cells are resistant to the effects of X-irradiation. The total number of beta-adrenergic receptors per cerebellum, measured by Scatchard analysis of saturation isotherms of specific [125I]iodohydroxybenzylpindolol (IHYP) binding, was reduced by 70--80% in 2-, 6- and 12-week-old animals. The relative proportion of beta 1- and beta 2-receptors was determined by analyzing the inhibition of specific IHYP binding by the beta 1 selective antagonist practolol. The total number of beta 2-adrenergic receptors per cerebellum was reduced by 81--83% in 6- and 12-week-old X-irradiated rats. However, the number of beta 1-adrenergic receptors per cerebellum in 6- and 12-week-old X-irradiated rats was not significantly different from that in control animals. The results suggest that beta 2 receptors in the rat cerebellum are primarily associated with the small interneurons destroyed by neonatal X-irradiation. The beta 1 receptors may be located on a cell population which is unaffected by this treatment, possibly on cerebellar Purkinje cells.
尽管β2 - 肾上腺素能受体在成年大鼠小脑中占主导地位，但也存在少量的β1 - 受体。为了研究β1 - 和β2 - 肾上腺素能受体的细胞定位，确定了聚焦于小脑的间歇性新生期X射线照射对β - 肾上腺素能受体两种亚型密度的影响。这种处理会破坏包括颗粒细胞、篮状细胞和星状细胞在内的晚期成熟小脑中间神经元。在2周、6周和12周龄的动物中观察到小脑质量损失60 - 70%。大型早期成熟的浦肯野细胞对X射线照射的影响具有抗性。通过对特异性[125I]碘羟基苄基吲哚洛尔（IHYP）结合的饱和等温线进行Scatchard分析来测量，每小脑β - 肾上腺素能受体的总数在2周、6周和12周龄的动物中减少了70 - 80%。通过分析β1选择性拮抗剂心得宁对特异性IHYP结合的抑制作用来确定β1 - 和β2 - 受体的相对比例。在6周和12周龄接受X射线照射的大鼠中，每小脑β2 - 肾上腺素能受体的总数减少了81 - 83%。然而，6周和12周龄接受X射线照射的大鼠中，每小脑β1 - 肾上腺素能受体的数量与对照动物相比无显著差异。结果表明，大鼠小脑中的β2受体主要与新生期X射线照射破坏的小中间神经元相关。β1受体可能位于不受这种处理影响的细胞群体上，可能是小脑浦肯野细胞。
