Meyer J H
Am J Physiol. 1980 Sep;239(3):G133-5. doi: 10.1152/ajpgi.1980.239.3.G133.
The lack of reliably quantitative methods has delayed understanding how the stomach empties and processes foods. Rapid refinement of gamma cameras has prompted the development of several methods for labeling of ordinary foods with radionuclides. These methods allow rapid labeling with tightly adherent nuclides and are safe for studies both in animals and humans. Nuclide-labeled foods have also permitted detailed analyses of gastric emptying in animals prepared with chronic duodenal fistulas. Early results indicate that the stomach retains foods until these are fragmented into particles smaller than 0.5 mm in diameter, and that this sieving is achieved in the antral region of the stomach. The speed of fragmentation of foods into particles of this size as well as the speed of emptying appear to be closely regulated by chemoceptive mechanisms in the small intestine, which can inhibit these processes. Thus, chemical composition of the meal regulates gastric emptying as well as the physical nature of the food, which determines how easily it can be fragmented by the stomach.
缺乏可靠的定量方法延缓了对胃如何排空和处理食物的理解。γ相机的迅速改进促使了几种用放射性核素标记普通食物的方法的发展。这些方法允许用紧密附着的核素进行快速标记，并且对动物和人体研究都是安全的。核素标记食物还使得对患有慢性十二指肠瘘的动物的胃排空进行详细分析成为可能。早期结果表明，胃会保留食物，直到食物被破碎成直径小于0.5毫米的颗粒，并且这种筛选是在胃的窦部区域完成的。食物破碎成这种大小颗粒的速度以及排空速度似乎受到小肠中化学感受机制的密切调节，这种机制可以抑制这些过程。因此，膳食的化学成分调节胃排空以及食物的物理性质，而食物的物理性质决定了它被胃破碎的难易程度。
