Li Z, Ruan Y, Guo Z D, Cong H, Zhang K Y, Takemura H
Department of Pharmacology, Sapporo Medical College, Japan.
Res Commun Chem Pathol Pharmacol. 1990 Jan;67(1):31-42.
The contractile response to acetylcholine (ACh) and the binding of [3H]-quinuclidinyl benzilate [( 3H]QNB) to muscarinic receptors in both longitudinal and circular muscles were examined in fundus, body and antrum of human stomach which was obtained by surgical operation for gastric cancer or ulcer. The values of pD2 and pA2 for ACh and atropine, respectively, on longitudinal muscle of fundus were similar to those of body but were larger than those of antrum. On the other hand, the values of pD2 and pA2 on circular muscles were not different among fundus, body, and antrum and were similar to those on longitudinal muscle of antrum. By Scatchard analysis of receptor binding of [3H]QNB in homogenate, at least two subclasses of binding sites, i.e. high and low affinity sites, were observed in fundus and body, while only high affinity binding site was found in antrum. Thus, we conclude that there are at least two subclasses of muscarinic receptors which regulate the contraction of smooth muscle in different regions of human stomach.
对因胃癌或溃疡而接受手术切除的人胃底、胃体和胃窦的纵肌和环肌，检测了其对乙酰胆碱（ACh）的收缩反应以及[3H] - 喹核醇基苯甲酸酯（[3H]QNB）与毒蕈碱受体的结合情况。胃底纵肌上ACh和阿托品的pD2和pA2值分别与胃体相似，但大于胃窦。另一方面，环肌上的pD2和pA2值在胃底、胃体和胃窦之间无差异，且与胃窦纵肌上的值相似。通过对匀浆中[3H]QNB受体结合的Scatchard分析，在胃底和胃体中观察到至少两类结合位点，即高亲和力和低亲和力位点，而在胃窦中仅发现高亲和力结合位点。因此，我们得出结论，在人胃的不同区域至少存在两类调节平滑肌收缩的毒蕈碱受体亚类。
