Miller J A, Zahniser N R
Department of Pharmacology, University of Colorado Health Sciences Center, Denver 80262.
Neurobiol Aging. 1988 May-Jun;9(3):267-72. doi: 10.1016/s0197-4580(88)80064-2.
Age-related changes in beta-adrenergic receptor density in Fischer 344 rat brain were examined using in vitro 125I-pindolol (IPIN) binding and quantitative autoradiographic analysis. Localized protein concentrations were determined using a new quantitative histological technique, and these were used to normalize the densities of receptors. Saturation binding studies in brain sections revealed 40-50% decreases in beta-adrenergic receptor density in the thalamus of 23-25-month-old and the cerebellum and brainstem of both 18-19-month-old and 23-25-month-old compared to 4-6-month-old rats. The loss of cerebellar beta-adrenergic receptors may be correlated with reports of deficits in sensitivity to beta-adrenergic-mediated transmission in the cerebellum of aged rats. No changes in specific IPIN binding with age were observed in rat cortex or hippocampus. In all areas examined no age-related differences were observed in receptor affinity. No changes in protein concentration were found in any of the areas examined in the different aged animals. These results demonstrate a region-specific loss of beta-adrenergic receptors with age in the brain of Fischer 344 rats.
利用体外125I-吲哚洛尔（IPIN）结合和定量放射自显影分析，研究了Fischer 344大鼠脑中β-肾上腺素能受体密度的年龄相关变化。使用一种新的定量组织学技术测定局部蛋白质浓度，并用于标准化受体密度。脑切片的饱和结合研究显示，与4-6月龄大鼠相比，23-25月龄大鼠丘脑以及18-19月龄和23-25月龄大鼠小脑和脑干中的β-肾上腺素能受体密度降低了40-50%。小脑β-肾上腺素能受体的丧失可能与老年大鼠小脑中β-肾上腺素能介导传递敏感性缺陷的报道相关。在大鼠皮质或海马中未观察到特异性IPIN结合随年龄的变化。在所有检查区域中，未观察到受体亲和力存在年龄相关差异。在不同年龄动物的任何检查区域中均未发现蛋白质浓度的变化。这些结果表明，Fischer 344大鼠脑中β-肾上腺素能受体随年龄出现区域特异性丧失。
