Tchilian E Z, Zhelezarov I E, Petkov V V, Hadjiivanova C I
Department of Biochemistry, Faculty of Biology, Sofia University, Bulgaria.
Neuropeptides. 1990 Dec;17(4):193-6. doi: 10.1016/0143-4179(90)90035-w.
125I-insulin binding was studied in membrane preparations of olfactory bulb, frontal cortex, hippocampus and hypothalamus from mature (5-month-old) and aged (22-month-old) rats. In the young animals the highest level of specific insulin binding was found in the olfactory bulb, with lower values of specific insulin binding in the frontal cortex, hippocampus and hypothalamus. In the aged rats the specific insulin binding was not changed in the frontal cortex, hippocampus and hypothalamus as compared to the young ones. A significant decrease of total insulin binding was observed only in the olfactory bulbs of aged rats (0.67 +/- 0.04 pmol insulin/mg protein) as compared to the mature animals (1.3 +/- 0.08 pmol insulin/mg protein). Scatchard analysis of insulin binding data revealed that this decrease was due to changes in the number of binding sites rather than to changes in the affinity of insulin receptors. It was suggested that the decrease observed in insulin receptor number in olfactory bulbs of aged rats might be due to the atrophic changes in the structure of olfactory bulbs previously shown by electron microscopy for aged rats.
对来自成熟（5 个月大）和老年（22 个月大）大鼠的嗅球、额叶皮质、海马体和下丘脑的膜制剂进行了¹²⁵I -胰岛素结合研究。在幼龄动物中，嗅球中特异性胰岛素结合水平最高，额叶皮质、海马体和下丘脑的特异性胰岛素结合值较低。与幼龄大鼠相比，老年大鼠额叶皮质、海马体和下丘脑的特异性胰岛素结合没有变化。仅在老年大鼠的嗅球中观察到总胰岛素结合显著降低（0.67±0.04 pmol 胰岛素/毫克蛋白质），而成熟动物为（1.3±0.08 pmol 胰岛素/毫克蛋白质）。对胰岛素结合数据的 Scatchard 分析表明，这种降低是由于结合位点数量的变化，而不是胰岛素受体亲和力的变化。有人提出，老年大鼠嗅球中观察到的胰岛素受体数量减少可能是由于先前电子显微镜显示的老年大鼠嗅球结构的萎缩性变化。
