新型M受体激动剂OTS对离体大鼠四种组织M受体亚型的选择性作用

Selective effects of new type M receptor agonist OTS on M receptor located in iso1ated four tissues of rat

采用离体大鼠皮层海马、纹状体、心房肌及胰腺组织,借助M受体分子探针3H-QNB对上述四种组织进行实验,观察OTS对M受体的亚型选择性作用.结果显示3H-QNB与上述四种组织亲和力相似,M受体密度以皮层海马、纹状体为高,心房肌、胰腺较低,比较OTS对上述四种组织M受体竞争抑制常数Ki,显示OTS对心脏组织M2受体有较强的选择性作用.

Using ^3H-QNB as a radioligand binding assay, selectivity of OTS on M receptor subtypes,which are located in isolated brain cortex hippocampus, brain striatum, atria and pancreas tissues of rat, was measured. Saturation assay showed that affinity of ^3H-QNB to the above four tissues was similar and density of M receptor was higher in brain cortex hippocampus and brain striarum than that in atria and pancreas. Ki values derived from competitive inhibiting experiments of OTS to ^3H-QNB on homogenates of four tissues suggested that OTS had high cardiac M2 receptor selectivity.