Smith G T, Moran T H, Coyle J T, Kuhar M J, O'Donahue T L, McHugh P R
Am J Physiol. 1984 Jan;246(1 Pt 2):R127-30. doi: 10.1152/ajpregu.1984.246.1.R127.
In an effort to identify target sites within the gastrointestinal (GI) tract through which cholecystokinin (CCK) may exert its gastric inhibitory and satiety effects, the distribution of CCK receptors was mapped in the stomach and small bowel by in vitro radiography utilizing 125I-labeled Bolton-Hunter CCK-33. Specific receptor binding was localized to the circular smooth muscle layer of the pyloric sphincter. Negligible binding was observed in the oblique, circular, or longitudinal muscle layers of other GI levels. Moderate nonspecific binding was associated with mucosal tissue in all gastric sections. The restriction of CCK receptors to the circular smooth muscle of the pyloric sphincter suggests this location as the site through which CCK inhibits gastric emptying. Gastric distension secondary to this inhibition may be the mechanism for CCK-induced satiety.
为了确定胆囊收缩素（CCK）可能通过其发挥胃抑制和饱腹感作用的胃肠道（GI）内的靶点，利用125I标记的博尔顿-亨特CCK-33通过体外放射自显影法绘制了CCK受体在胃和小肠中的分布图。特异性受体结合定位于幽门括约肌的环形平滑肌层。在其他胃肠道水平的斜肌、环肌或纵肌层中观察到的结合可忽略不计。在所有胃切片中，中度非特异性结合与黏膜组织有关。CCK受体局限于幽门括约肌的环形平滑肌表明该位置是CCK抑制胃排空的部位。这种抑制继发的胃扩张可能是CCK诱导饱腹感的机制。
