Meyer J H, Dressman J, Fink A, Amidon G
Gastroenterology. 1985 Oct;89(4):805-13. doi: 10.1016/0016-5085(85)90576-1.
Previous studies suggested that the food-containing canine stomach retains large, nondigestible spheres until all food has emptied; but it is not known whether there is a threshold size or a gradation of sizes that will empty along with food. Further, nothing is known of the effects of such parameters as density, shape, and surface energy on the emptying of nondigestible particles of any given size. To answer these questions 6 dogs with chronic duodenal fistulas were studied. Radiolabeled food and spheres were collected from the fistulas to compare the rate of gastric emptying of the spheres with that of the food. After a standard test meal of 99mTc-labeled liver, steak, and water, diverted chyme was collected over a stack of sieves in 30-min fractions over 5 postcibal hours. The percent of fed spheres and fed 99mTc-labeled liver in each collection was counted, and liquid chyme was returned to the distal duodenum. Spheres with a density of 1 emptied progressively faster as sphere diameters were decreased from 5 to 1 mm; but 0.015-mm spheres emptied at about the same rate as those with diameters of 1 mm. Emptying of the spheres became similar to emptying of the 99mTc-labeled liver at about 1.6 mm. Spheres with densities less than 1 or greater than 1 emptied more slowly than spheres of the same size with a density of 1, whereas paper squares emptied the same way as spheres of comparable size and density. Surface energy did not affect emptying. The findings indicated that both sphere size and density affect their emptying in the presence of food.
先前的研究表明，装有食物的犬胃会保留大的、不可消化的球体，直到所有食物排空；但尚不清楚是否存在一个临界尺寸或尺寸分级，这些球体是否会与食物一起排空。此外，对于密度、形状和表面能等参数对任何给定尺寸的不可消化颗粒排空的影响，人们一无所知。为了回答这些问题，对6只患有慢性十二指肠瘘的狗进行了研究。从瘘管收集放射性标记的食物和球体，以比较球体与食物的胃排空率。在食用含有99mTc标记的肝脏、牛排和水的标准测试餐后，在进食后的5个小时内，每隔30分钟收集一次通过一叠筛网分流的食糜。计算每次收集物中喂食的球体和喂食的99mTc标记肝脏的百分比，并将液体食糜返回十二指肠远端。密度为1的球体，随着球体直径从5毫米减小到1毫米，排空速度逐渐加快；但直径为0.015毫米的球体排空速度与直径为1毫米的球体大致相同。球体在直径约为1.6毫米时的排空情况与99mTc标记肝脏的排空情况相似。密度小于1或大于1的球体比相同大小、密度为1的球体排空更慢，而纸方块的排空方式与大小和密度相当的球体相同。表面能不影响排空。研究结果表明，在有食物的情况下，球体的大小和密度都会影响其排空。
