Simmons T C, Hogan D L, Selling J A, Maxwell V, Isenberg J I
J Clin Gastroenterol. 1986 Apr;8(2):146-9. doi: 10.1097/00004836-198604000-00008.
When ingested 1 hour after a meal, conventional liquid antacids have a buffering effect of approximately 2 hours, while in the fasting state their effect is brief, lasting less than 1 hour. We tested the hypothesis that equal doses of antacid, one water soluble (sodium bicarbonate) and the other water insoluble (aluminum hydroxide plus magnesium hydroxide, MaaloxR), would have similar durations of postprandial buffering if the water soluble antacid regenerates the particulate protein buffer of the meal that leaves the stomach more slowly than liquids. Tests were conducted in random order on three separate days in 10 patients with duodenal ulcer. The effects of 30 ml of 2.39 M sodium bicarbonate (6.17 g, about 1 teaspoonful), the aluminum-magnesium antacid, each equivalent to 71.7 mmol of in vitro buffer, and water as a control on pH, hydrogen ion activity, and titratable acidity were compared. Thirty milliliters of each was swallowed 1 and 3 hours after ingestion of a standard solid plus liquid. Compared to the water control each dose of sodium bicarbonate significantly increased intragastric pH and decreased hydrogen ion activity and titratable acidity for only 1 hour. Each dose of the aluminum-magnesium antacid significantly buffered intragastric contents for 2 hours. These findings indicate that sodium bicarbonate transiently buffers postprandial intragastric contents. Therefore, sodium bicarbonate fails to reconstitute the protein buffer of the meal effectively, and the observations suggest that it leaves the stomach rapidly with the liquid phase of the meal. However, the water insoluble, aluminum-magnesium antacid has a longer duration of buffering, probably because it leaves the stomach more slowly, largely with the solid portion of the meal.
餐后1小时摄入时，传统液体抗酸剂具有约2小时的缓冲作用，而在禁食状态下其作用短暂，持续时间不到1小时。我们测试了这样一个假设：如果水溶性抗酸剂能再生餐食中的颗粒状蛋白质缓冲物，且该缓冲物离开胃的速度比液体慢，那么等量的抗酸剂，一种是水溶性的（碳酸氢钠），另一种是水不溶性的（氢氧化铝加氢氧化镁，胃仙-U），餐后缓冲持续时间将相似。在10名十二指肠溃疡患者中，于三个不同日期按随机顺序进行了测试。比较了30毫升2.39M碳酸氢钠（6.17克，约1茶匙）、铝镁抗酸剂（每种相当于71.7毫摩尔体外缓冲剂）以及作为对照的水对pH值、氢离子活性和可滴定酸度的影响。在摄入标准固体加液体1小时和3小时后，分别吞服30毫升每种物质。与水对照相比，每剂碳酸氢钠仅在1小时内显著提高胃内pH值，降低氢离子活性和可滴定酸度。每剂铝镁抗酸剂能显著缓冲胃内容物2小时。这些发现表明碳酸氢钠能短暂缓冲餐后胃内容物。因此，碳酸氢钠不能有效地重建餐食中的蛋白质缓冲物，这些观察结果表明它会随着餐食的液相迅速离开胃。然而，水不溶性的铝镁抗酸剂具有更长的缓冲持续时间，可能是因为它离开胃的速度更慢，主要随着餐食的固体部分。
