Isolation and purification of gastric inhibitors from canine gastrointestinal mucosa

已经表明切除狗胃的泌酸粘膜去除了一种强有力的抑制剂，我们试图从狗胃底粘膜中初步分离抑制剂。从煮沸的、均质化的犬胃粘膜中在2%冷三氟乙酸（TFA）中提取抑制剂，离心、过滤并冻干。将冻干提取物溶于水中，并首先在Sephadex G10上纯化。在用0.1%TFA洗脱的盐峰级分中发现抑制剂。将这些级分合并，加载到反相C18柱上并通过HPLC纯化。在大鼠中对五肽胃泌素刺激的酸分泌测试级分的抑制活性。抑制剂不保留在HPLC上，并且在酸性和碱性条件下进行醚萃取后，将抑制剂浓缩在水/脂质溶剂系统的水相中。这表明抑制剂是一种带电的两性离子物质，可能是一种小蛋白质

Having shown that excision of the oxyntic mucosa of the dog stomach removes a powerful inhibitor, we attempted preliminary isolation of the inhibitor from canine fundic mucosa. The inhibitor was extracted from boiled, homogenized canine gastric mucosa in 2 % cold trifluoroacetic acid (TFA), centrifuged, filtrated and lyophilized. The lyophilized extract was dissolved in water and first purification on Sephadex G10. The inhibitor was found in the salt peak fractions on elution with 0.1 % TFA. These fractions were pooled, loaded onto a reverse-phase C18 column and purified by HPLC. Inhibitory activity of the fractions was tested on pentagastrin-stimulated acid secretion in the rat. The inhibitor is not retained on the HPLC and after ether extraction under both acidic and alkaline condition, the inhibitor was concentrated in aqueous phase of an aqueous/lipid solvent system. This suggests that the inhibitor is a charged, zwitterionic substance, possible a small protein