胃酸度对肠道锌吸收的影响

本研究采用全肠道灌洗法测定了２０例健康老年人（５６～７４岁，平均６６．７±４．６岁）空腹状态下的胃液酸度（ｐＨ）及药物（奥美拉唑２０ｍｇ，每天二次连续３天）改变胃酸度前、后的肠道锌吸收率。结果，受检者空腹状态下胃液ｐＨ为３．３±０．４０，用药后胃液ｐＨ明显上升为６．８±０．０３（Ｐ＜０．０１）；而肠道锌吸收率分别为８５．４％与７９．５％，二者无明显统计学差异（Ｐ＞０．０５）。研究表明，２０例健康老年人空腹状态下呈低胃酸状态，服用奥美拉唑后，胃内酸度进一步降低，但对肠道锌吸收并无明显影响。

EFFECT OF GASTRIC ACIDITY ON INTESTINAL ABSORPTION OF ZINC FROM FOOD IN THE ELDERLY

o investigate the importance of gastric acidity for zinc absorption in the elderly population,a group of 20 apparently healthy elderly was stu一died by comparing their gastric acidity at basal(fasting) condition and zinc absorption using a whole- gut absorption technique before and after Omepra-zole(OM) treatment. The results showed that intragastric pH determined at basal condition before and OM treatment was 3.3±0.40 and 6.8 ±0.03,respectively,indicating a decline in gastric acidity by OM treatment.Zinc excretion l1nder basal condition was 79.5 ± 12.3μmol(5.2 ± 0.7mg)over a12h absorptive period.The mean apparent zine absorption from test meal (steamed whole wheat bread) before OM treatment was 30.5±8.9μmol (1.9±0.4mg),Which was not different from that after OM treatment,24.1±6.5μmol(1.4±0.3mg),P>0.05.After correcting for the amount of basalzinc excrction (79.5μmol, or 5.2mg),true zinc absorption before and afterOM treatment Were continue to be similar,i.e. ,108.4 ±16.7μmol (7.1±1.2mg, and 100.9±16. 5μmol (6.6±1.1mg),P>0.05. Thecorresponding frac- tional absorption before and after OM treatment was 85.4 ±13.4%and79.5 ±13%, respectively. These results demonstrated that lower gastric aci- dity was common in the elderly,and was further decreased after OM treat- ment; however, zinc absorption was not affected by a decline in gastricaciditv after OM treatment.