Takahashi S, Igarashi H, Nakamura K, Masubuchi N, Saito S, Aoyagi T, Itoh T, Hirata I
Third Department of Internal Medicine, Kyorin University School of Medicine.
Nihon Rinsho. 1993 Dec;51(12):3149-53.
The ammonia concentration in the gastric juice from H. pylori positive cases was significantly higher than that from negative cases, and there was positive correlation between number of H. pylori, gastritis score and ammonia concentration in gastric juice. It is suggested that ammonia in gastric juice which is produced by powerful urease activity of H. pylori is one of the pathogenic factors in gastritis. We succeeded in producing a urease-negative mutant strain of H. pylori. This strain did not colonize gastric mucosa of Cynomolgus monkeys. H. pylori survival time in vitro was increased at pH 2.0 in the presence of urea. These results suggest that urease facilitates colonization of gastric mucosa by H. pylori, and prolongs the survival of H. pylori in an acidic environment.
幽门螺杆菌阳性病例胃液中的氨浓度显著高于阴性病例，且幽门螺杆菌数量、胃炎评分与胃液中氨浓度之间呈正相关。提示幽门螺杆菌强大的脲酶活性产生的胃液中的氨是胃炎的致病因素之一。我们成功培育出幽门螺杆菌脲酶阴性突变株。该菌株未在食蟹猴胃黏膜定植。在有尿素存在的情况下，幽门螺杆菌在体外pH 2.0时的存活时间延长。这些结果表明，脲酶促进幽门螺杆菌在胃黏膜的定植，并在酸性环境中延长幽门螺杆菌的存活时间。
