Pallotta N, Cicala M, Frandina C, Corazziari E
Università La Sapienza Cattedra di Gastroenterologia I, Clinica Medica II, Policlinico Umberto I, Università Campus Biomedico, Rome, Italy.
Am J Gastroenterol. 1998 Dec;93(12):2513-22. doi: 10.1111/j.1572-0241.1998.00598.x.
The present study aimed to evaluate the patterns of antral contractility and pylorus opening and closure in relation to transpyloric flow of a nutrient liquid meal.
Ultrasound images of the antro-pyloro-duodenal tract were continuously tape-recorded in healthy volunteers for 1 h postprandially and were reviewed twice later by independent observers. Episodes and patterns of pylorus opening and closure, antral-wall contractions, and transpyloric flow were assessed separately and their time relations were identified.
Transpyloric flow (forward, 56%+/-13%; retrograde, 19%+/-11%; and to and fro, 25%+/-14%) occurred essentially during episodes of prolonged pylorus opening not associated with occlusive antral or duodenal proximal contraction, which represented the antro-pyloro-duodenal common chamber. The antro-pyloro-duodenal common chamber lasted on average 36+/-12 s and represented 41%+/-12% of the total observation period. Different patterns of antral contractions were identified according to whether they reached or occluded the terminal antrum and pylorus. Preterminal antral contractions (46%+/-12%) did not propagate beyond the proximal two thirds of the antrum. Terminal antral contractions (54%+/-12%) propagated along the entire antrum and could either occlude (20%+/-9%) or not occlude (42%+/-17%) the lumen. Pyloric opening independent of antral contractions and related to nonocclusive antral contractions could occur equally at the onset of the antro-pyloro-duodenal common chamber. Pyloric closure independent of antral contractions put an end to transpyloric flow in 73%+/-6% of the antro-pyloro-duodenal common chamber.
The final passage of contents from the stomach to the duodenum after the ingestion of a caloric liquid meal is the result of one or more episodes of uni- or bi-directional transpyloric flow, which are regulated by several motor events. The contractile states of the antrum and pylorus show specific features that variably interrelate to provide mixing and to regulate the transpyloric flow of ingesta. A crucial regulator of transpyloric flow appears to be the spatio-temporal relation between antral contractions and pyloric closure rather than the contractile events per se. An equal number of pyloric openings related, and unrelated, to antral contractions appears to determine the onset of the antro-pyloro-duodenal common chamber and, thus, of transpyloric flow. Pyloric closure unrelated to antral contractions appears to be the main mechanism that interrupts transpyloric flow. In conclusion, it appears that the antro-pyloro-duodenal tract acts as a functional unit in the digestion of a liquid caloric meal.
本研究旨在评估胃窦收缩及幽门开闭模式与营养液餐经幽门流动的关系。
对健康志愿者餐后1小时的胃窦 - 幽门 - 十二指肠段超声图像进行连续录像，随后由独立观察者复查两次。分别评估幽门开闭、胃窦壁收缩及经幽门流动的发作情况和模式，并确定它们的时间关系。
经幽门流动（正向，56%±13%；逆向，19%±11%；往返，25%±14%）主要发生在幽门长时间开放且与胃窦或十二指肠近端非闭塞性收缩无关的时段，此即胃窦 - 幽门 - 十二指肠共同腔。胃窦 - 幽门 - 十二指肠共同腔平均持续36±12秒，占总观察期的41%±12%。根据胃窦收缩是否到达或闭塞胃窦末端及幽门，确定了不同的胃窦收缩模式。胃窦终末前收缩（46%±12%）未超过胃窦近端三分之二。胃窦终末收缩（54%±12%）沿整个胃窦传播，可闭塞（20%±9%）或不闭塞（42%±17%）管腔。与胃窦收缩无关且与非闭塞性胃窦收缩相关的幽门开放，在胃窦 - 幽门 - 十二指肠共同腔开始时同等可能出现。与胃窦收缩无关的幽门关闭在73%±6%的胃窦 - 幽门 - 十二指肠共同腔中终止了经幽门流动。
摄入热量性液体餐后，胃内容物最终进入十二指肠是单向或双向经幽门流动的一次或多次发作的结果，这些发作受多种运动事件调节。胃窦和幽门的收缩状态呈现出特定特征，它们相互关联以实现混合并调节食糜的经幽门流动。经幽门流动的关键调节因素似乎是胃窦收缩与幽门关闭之间的时空关系，而非收缩事件本身。与胃窦收缩相关和不相关的幽门开放数量相等，似乎决定了胃窦 - 幽门 - 十二指肠共同腔的开始以及经幽门流动的开始。与胃窦收缩无关的幽门关闭似乎是中断经幽门流动的主要机制。总之，胃窦 - 幽门 - 十二指肠段在热量性液体餐的消化过程中似乎起着功能单元的作用。
