Klaassen A B, Kuijpers W, Scheres H M, Rodrigues de Miranda J F, Beld A J
Arch Otolaryngol Head Neck Surg. 1986 Apr;112(4):428-31. doi: 10.1001/archotol.1986.03780040068013.
Radioligand receptor binding might give more detailed information on the innervation pattern of the nasal mucosa and the character of the various neuroreceptors involved. With respect to the cholinergic receptors, this technique reveals that specific binding of tritiated I-quinuclidinyl benzilate to rat nasal mucosa homogenates occurs to a homogeneous class of binding sites, with a dissociation constant of 0.06 +/- 0.02 nM and a receptor density of 8 +/- 2 pmole/g of tissue. Binding is stereoselectively inhibited by benzetimide hydrochloride enantiomers. Pirenzepine displacement (inhibition constant = 0.5 X 10(-6) M) classifies tritiated I-quinuclidinyl benzilate binding sites as M2-muscarinic receptors. Methylfurthrethonium inhibits tritiated I-quinuclidinyl benzilate binding at high concentrations, pointing to the presence of low-affinity agonist binding sites, probably admixed with a small proportion of high-affinity agonist binding sites. These data obtained in the rat open new perspectives for studying muscarinic receptors in the human nose to elucidate the supposed disturbance of autonomic nerve regulation in nasal hyperreactivity.
放射性配体受体结合可能会提供有关鼻黏膜神经支配模式以及所涉及的各种神经受体特性的更详细信息。就胆碱能受体而言，该技术显示，氚标记的碘代喹宁环苯酸盐与大鼠鼻黏膜匀浆的特异性结合发生在一类同质的结合位点上，解离常数为0.06±0.02 nM，受体密度为8±2 pmol/g组织。盐酸苯乙苄胺对映体可立体选择性地抑制结合。哌仑西平置换（抑制常数 = 0.5×10⁻⁶ M）将氚标记的碘代喹宁环苯酸盐结合位点归类为M2毒蕈碱受体。甲基呋氨甲酰胆碱在高浓度时抑制氚标记的碘代喹宁环苯酸盐结合，表明存在低亲和力激动剂结合位点，可能混有一小部分高亲和力激动剂结合位点。在大鼠中获得的这些数据为研究人类鼻子中的毒蕈碱受体开辟了新的视角，以阐明鼻高反应性中自主神经调节的假定紊乱。
