Hollander D, Tarnawski H
Gerontology. 1985;31(3):133-7. doi: 10.1159/000212694.
The intestinal permeability of aging rats to various molecular weight species of polyethylene glycol 400 (PEG 400) was studied. Animals received a bolus of PEG 400 by oral gavage and urine was collected for 6 h to assess its rate of absorption. Quantitation by gas liquid chromatography revealed that total urinary excretion of PEG 400 increased with aging. 34-week-old rats excreted 34.3% of the administrated dose while 43.6% was excreted in the urine by rats 133 weeks of age. This effect was more pronounced with the higher molecular weight PEG since excretion of the lower molecular weight PEG 282 decreased by 10.5% while PEG 634 excretion increased by 11.4% with aging. The increased permeability of the intestinal tract to higher molecular weight species of PEG may indicate that the intestinal protective barrier to the absorption of potentially harmful environmental substances may be less efficient in aging animals. If similar findings are found in aging humans, they may indicate increased potential for absorption of large antigenic or carcinogenic compounds from the intestinal lumen.
研究了衰老大鼠对不同分子量聚乙二醇400（PEG 400）的肠道通透性。动物通过口服灌胃给予一剂PEG 400，并收集6小时尿液以评估其吸收速率。气相色谱法定量显示，PEG 400的总尿排泄量随衰老而增加。34周龄大鼠排泄了给药剂量的34.3%，而133周龄大鼠尿液中排泄了43.6%。这种效应在较高分子量的PEG中更为明显，因为较低分子量的PEG 282排泄量下降了10.5%，而PEG 634排泄量随衰老增加了11.4%。肠道对较高分子量PEG的通透性增加可能表明，衰老动物肠道对潜在有害环境物质吸收的保护屏障效率较低。如果在衰老人类中发现类似结果，可能表明从肠腔吸收大的抗原性或致癌性化合物的可能性增加。
