Gastric muscle contractions grind and mix solid/liquid meal within the stomach, and move it into the bowels at a controlled rate. Contractions are of two types: slow volume-reducing contractions of the proximal stomach (the fundus), and peristaltic contraction waves in the distal stomach (the antrum). Fundic squeeze maintains gastro-duodenal pressure difference to drive gastric emptying. Emptying is generally assumed to proceed from the antrum to the fundus, so that ingested drugs can take hours to enter the small intestines and activate. Antral contraction waves (ACW), in contrast, generate fluid motions that break down and mix gastric content. Using a computer model of the human stomach, we discover a new function of these contraction waves apart from grinding and mixing. In coordination with fundic contraction, antral contraction waves move liquid content from the fundus along a very narrow path to the duodenum through the center of the antrum. Using physiological data, we show that this gastric emptying "Magenstrasse" (stomach road) can funnel liquid gastric content from the farthest reaches of the fundus directly to the intestines within 10 min. Consequently, whereas drugs (tablets, capsules, liquid) released off the Magenstrasse may require hours to enter the duodenum, at low concentration, when released on the Magenstrasse the drug can enter the duodenum and activate within 10 min-at high concentration. This discovery might explain observed high variability in drug initiation time, and may have important implications to both drug delivery and digestion, as well as to other wall-driven emptying of elastic containers.

译文

胃肌肉收缩在胃内研磨和混合固体/液体食物,并以受控的速度将其移入肠道。收缩有两种类型: 近端胃 (眼底) 的缓慢减容收缩和远端胃 (胃窦) 的蠕动收缩波。胃底挤压可维持胃十二指肠压差,以驱动胃排空。排空一般假设是从胃窦到眼底进行,这样摄入的药物可能需要几个小时才能进入小肠并激活。相反,窦收缩波 (ACW) 会产生分解并混合胃内容物的液体运动。使用人类胃的计算机模型,除了研磨和混合之外,我们还发现了这些收缩波的新功能。与胃底收缩相协调,胃窦收缩波将液体含量从眼底沿非常狭窄的路径穿过胃窦中心到达十二指肠。使用生理数据,我们表明这种胃排空的 “Magenstrasse” (胃路) 可以在10分钟内将液体胃内容物从最远处的眼底直接漏斗到肠道。因此,尽管从Magenstrasse释放的药物 (片剂,胶囊,液体) 可能需要数小时才能进入十二指肠,但在低浓度下,当在Magenstrasse上释放时,药物可以进入十二指肠并在10分钟内激活-高浓度。这一发现可能解释了观察到的药物起始时间的高变异性,并且可能对药物输送和消化以及其他壁驱动的弹性容器排空具有重要意义。

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