Mao Y K, Wang Y F, Daniel E E
Department of Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada.
Peptides. 1995;16(6):1025-9. doi: 10.1016/0196-9781(95)00072-r.
We localized and characterized the binding of 3H-L364,718 in canine small intestine circular muscle. The highest densities of [3H]L364,718 binding were located in the fraction enriched in deep muscular plexus synaptosomal membranes. In this fraction [3H]L364,718 binding was of high density (Bmax 136.78 +/- 53.66 fmol/mg) and high affinity (Kd 1.67 +/- 0.74 nM). Kinetics studies revealed that binding was reversible and yielded a similar Kd value. L364,718, CCK-8-S, and L365,260 fully displaced [3H]L364,718 binding, but ligands at CCKB receptors, gastrin-17, and YM022 did not. Therefore, CCKA receptors in canine intestine circular muscle are located on nerve endings.
我们对3H-L364,718在犬小肠环形肌中的结合进行了定位和特性分析。[3H]L364,718结合的最高密度位于富含深层肌丛突触体膜的组分中。在该组分中，[3H]L364,718结合具有高密度（Bmax为136.78 +/- 53.66 fmol/mg）和高亲和力（Kd为1.67 +/- 0.74 nM）。动力学研究表明结合是可逆的，并且产生了相似的Kd值。L364,718、CCK-8-S和L365,260可完全取代[3H]L364,718的结合，但CCKB受体的配体胃泌素-17和YM022则不能。因此，犬肠环形肌中的CCKA受体位于神经末梢上。
