乙酰水杨酸对胃黏液黏度、氢离子通透性及对胃蛋白酶敏感性的影响。

Effect of acetylsalicylic acid on gastric mucin viscosity, permeability to hydrogen ion, and susceptibility to pepsin.

作者信息

Sarosiek J, Mizuta K, Slomiany A, Slomiany B L

出版信息

Biochem Pharmacol. 1986 Dec 1;35(23):4291-5. doi: 10.1016/0006-2952(86)90708-2.

Abstract

The effect of acetylsalicylic acid (aspirin) on peptic degradation of gastric mucin, its viscosity and the ability to retard the diffusion of hydrogen ion was investigated. The results of peptic degradation indicated that, in the absence of the drug, the rate of proteolysis was proportional to mucin concentration up to 400 micrograms and remained constant with time for up to 1 hr. Introduction of aspirin led to an enhancement in the rate of proteolysis. The apparent Km value of pepsin toward mucus glycoprotein was 8.7 X 10(-7) M in the absence of the drug and 6.9 X 10(-7) M in its presence. Viscosity measurements showed a drop in mucin viscosity following preincubation with aspirin. This decrease was concentration dependent and at a 4.0 X 10(-5) M concentration of the drug reached a value of 75%. Permeability studies revealed that preincubation with 2.0 X 10(-5) M aspirin increased the permeability of mucin to hydrogen ion by 10%, while an 18% increase was obtained with 4.0 X 10(-5) M aspirin. The results suggest that aspirin weakens the integrity of the gastric mucus layer by promoting its peptic degradation, decreasing viscosity, and reducing the ability to resist hydrogen ion penetration.

摘要

研究了乙酰水杨酸（阿司匹林）对胃黏液的消化降解、其黏度以及阻止氢离子扩散能力的影响。消化降解结果表明，在无药物存在时，蛋白水解速率在黏液浓度达400微克之前与黏液浓度成正比，且在长达1小时的时间内随时间保持恒定。加入阿司匹林导致蛋白水解速率加快。在无药物存在时胃蛋白酶对黏液糖蛋白的表观米氏常数（Km值）为8.7×10⁻⁷M，在有药物存在时为6.9×10⁻⁷M。黏度测量显示，黏液与阿司匹林预孵育后黏度下降。这种下降与浓度有关，在药物浓度为4.0×10⁻⁵M时降至75%。通透性研究表明，用2.0×10⁻⁵M阿司匹林预孵育使黏液对氢离子的通透性增加10%，而用4.0×10⁻⁵M阿司匹林则使通透性增加18%。结果表明，阿司匹林通过促进胃黏液层的消化降解、降低黏度以及减弱抵抗氢离子渗透的能力，削弱了胃黏液层的完整性。