Chowdhury J R, Berkowitz J M, Praissman M, Fara J W
Am J Physiol. 1975 Nov;229(5):1311-5. doi: 10.1152/ajplegacy.1975.229.5.1311.
Effects of OP-CCK, gastrin, and secretin were studied on isometric tension development in strips of cat gallbladder. Effective molar concentrations were 2.2 X 10(-10) to 5.3 X 10(-9) for OP-CCK, and 1.13 X 10(-7) to 1.5 X 10(-6) for gastrin. The maximal response to gastrin averaged 66% the maximal response to OP-CCK and effects were not blocked by atropine. Secretin was weakly stimulatory or ineffective by itself. Prior addition of submaximal doses of gastrin shifted the dose-response curve of OP-CCK to the right, but neither the slope nor the calculated maximal response (CMR) was significantly changed. This suggests that gastrin and OP-CCK compete for a common receptor on cat gallbladder. On the other hand, a background dose of secretin shifted the dose-response curves for both OP-CCK and gastrin to the left and increased the slopes significantly with increase in the respective CMRs. The combined action of OP-CCK (or gastrin) and secretin are supra-additive. These experiments suggest that OP-CCK and gastrin act at a common receptor site which is different from the secretin-receptor site.
研究了蛙皮胆囊收缩素（OP-CCK）、胃泌素和促胰液素对猫胆囊条等长张力发展的影响。OP-CCK的有效摩尔浓度为2.2×10⁻¹⁰至5.3×10⁻⁹，胃泌素的有效摩尔浓度为1.13×10⁻⁷至1.5×10⁻⁶。胃泌素的最大反应平均为OP-CCK最大反应的66%，且其作用不受阿托品阻断。促胰液素本身的刺激作用较弱或无作用。预先加入次最大剂量的胃泌素可使OP-CCK的剂量反应曲线右移，但斜率和计算出的最大反应（CMR）均无明显变化。这表明胃泌素和OP-CCK在猫胆囊上竞争共同受体。另一方面，促胰液素的背景剂量可使OP-CCK和胃泌素的剂量反应曲线左移，并随着各自CMR的增加而显著增加斜率。OP-CCK（或胃泌素）与促胰液素的联合作用具有超相加性。这些实验表明，OP-CCK和胃泌素作用于一个与促胰液素受体位点不同的共同受体位点。
