DECREASED DENSITY OF BETA-ADRENERGIC AND MUSCARINIC CHOLINERGIC RECEPTOR-SITES IN THE VASA NERVORUM OF AGED RATS
DECREASED DENSITY OF BETA-ADRENERGIC AND MUSCARINIC CHOLINERGIC RECEPTOR-SITES IN THE VASA NERVORUM OF AGED RATS
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DOI：
10.1016/0047-6374(91)90038-2
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发表时间：
1991-11-01
影响因子：
5.3
通讯作者：
AMENTA, F
中科院分区：
文献类型：
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作者：
ZACCHEO, D;DEMICHELE, M;AMENTA, F
应用放射受体结合和光镜放射自显影技术，在坐骨神经切片中研究了神经血管β-肾上腺素能受体和毒蕈碱胆碱能受体的药理学特征和解剖学定位。使用4和24月龄的Sprague-Dawley大鼠。[H-3]二氢烯丙洛尔（DHA）和[H-3]奎宁环二苯乙酸酯（QNB）分别用于标记β-肾上腺素能和毒蕈碱胆碱能受体。在研究的2个年龄组中，以与β-肾上腺素能或毒蕈碱胆碱能受体标记一致的方式将配体与大鼠坐骨神经节段结合。解离常数（K（d））值（[H-3]DHA约为1.37 nM，[H-3]QNB约为0.75 nM）在4月龄和24月龄大鼠之间没有显著变化。与4月龄大鼠相比，24只大鼠中[H-3]DHA的最大结合位点浓度（B（max））降低了约35%。[H-3]QNB的B（max）值在老年大鼠中降低约50%。光镜放射自显影显示，在暴露于[H-3]DHA或[H-3]QNB的坐骨神经切片中，神经外膜和神经束膜动脉的中层中出现特异性银颗粒。24月龄大鼠神经外膜动脉和神经束膜动脉中形成的银颗粒数量明显低于4月龄动物。上述结果表明，神经血管的β-肾上腺素能受体和毒蕈碱胆碱能受体的密度发生了年龄依赖性的损失。
The pharmacological profile and the anatomical localization of beta-adrenergic and muscarinic cholinergic receptors of the vasa nervorum were studied in sections of sciatic nerve using radioreceptor binding and light microscope autoradiography techniques. Sprague-Dawley rats of 4 and 24 months of age were used. [H-3]Dihydroalprenolol (DHA) and [H-3]quinuclidinyl benzilate (QNB) were used to label beta-adrenergic and muscarinic cholinergic receptors, respectively. The ligands were bound to sections of rat sciatic nerve in a manner consistent with the labelling of beta-adrenergic or muscarinic cholinergic receptors in the 2 age groups investigated. The dissociation constant (K(d)) values (about 1.37 nM for [H-3]DHA and 0.75 nM for [H-3]QNB) did not significantly change between 4- and 24-month-old rats. The maximum concentration of binding sites (B(max)) for [H-3]DHA was decreased by about 35% in 24 in comparison with 4-month-old rats. The B(max) value for [H-3]QNB was reduced by about 50%, in the aged rats. Light microscope autoradiogaphy revealed the development of specific silver grains in the medial layer of epineurial and perineurial arteries in sections of sciatic nerve exposed either to [H-3]DHA or [H-3]QNB. The number of silver grains developed in epineurial and perineurial arteries of rats of 24 months is significantly lower than in animals of 4 months. The above results suggest the occurrence of an age-dependent loss in the density of beta-adrenergic and muscarinic cholinergic receptors of vasa nervorum.