Roberton A M, Rabel B, Stubbs L, Tasman-Jones C, Lee S P
School of Biological Sciences, University of Auckland, New Zealand.
Glycoconj J. 1996 Oct;13(5):781-9. doi: 10.1007/BF00702342.
The effect of aspirin on the rate of secretion and amino acid composition of human ileal mucin was studied, using subjects with ileal conduits as a model system in which mucin secreted from the ileal conduit tissue is flushed out in the urine and can be measured and analysed. Aspirin (600 mg per day, administered orally) increased the daily mucin output by 37-104% in subjects by days 3 or 4, but thereafter the mucin output declined to below the baseline level by day 10. Mucin samples, purified from the ileal conduit urine during the control period and during aspirin administration, were compared. There were no discernible changes in the degree of polymerisation or the density, but during aspirin administration the amino acid composition was significantly changed, and in particular threonine and proline were enriched. One possible explanation, consistent with the compositional analyses, is that the N- and C-terminal regions of the mucin subunits have been cleaved off and lost during aspirin administration. The observed changes in mucin secretion may have implications for the mechanism of the toxic effects of aspirin on the small intestine by altering the barrier properties of the mucus layer.
以回肠造口术患者作为模型系统，研究了阿司匹林对人回肠粘蛋白分泌速率和氨基酸组成的影响。在该模型系统中，回肠造口术组织分泌的粘蛋白会随尿液排出，从而可对其进行测量和分析。阿司匹林（每天口服600毫克）在第3天或第4天时使受试者的每日粘蛋白产量增加了37%至104%，但在第10天时，粘蛋白产量降至基线水平以下。对在对照期和服用阿司匹林期间从回肠造口术尿液中纯化的粘蛋白样本进行了比较。聚合度或密度没有明显变化，但在服用阿司匹林期间，氨基酸组成发生了显著变化，尤其是苏氨酸和脯氨酸含量增加。与成分分析结果一致的一种可能解释是，在服用阿司匹林期间，粘蛋白亚基的N端和C端区域被切断并丢失。观察到的粘蛋白分泌变化可能通过改变粘液层的屏障特性，对阿司匹林对小肠的毒性作用机制产生影响。
