Yeo C J, Bastidas J A, Schmieg R E, Zinner M J
Department of Surgery, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
Am J Physiol. 1990 Sep;259(3 Pt 1):G402-9. doi: 10.1152/ajpgi.1990.259.3.G402.
After a meal, the absorption of water and electrolytes from the jejunal lumen increases. This meal-induced jejunal absorption occurs in jejunal segments out of normal gastrointestinal continuity. The experimental model used 25-cm proximal jejunal Thiry-Vella loops in awake dogs (n = 72 observations) to evaluate the mechanisms involved in meal-induced jejunal absorption, seeking to define the source or sources of the proabsorptive signal. Specifically, we evaluated the jejunal absorptive response to a standard meal, a standard meal plus cholinergic blockage using atropine, a sham-fed meal, a gavage-fed meal, and gastric distension with balloon and gavage water. Both the standard meal and the gavage-fed meal induced a prompt, sustained, and significant (P less than 0.0001) increase in the absorption of H2O, Na+, and Cl-. Atropine significantly reduced the magnitude of the postmeal absorptive response (P less than 0.05) compared with the standard meal alone. The sham-fed meal, gastric balloon distension, and gavage water did not alter jejunal absorption. Vagal nerve integrity after cervical esophageal manipulation was verified by gastric acid output and gastrin response to stimuli. These data support a role for cholinergic modulation of meal-stimulated jejunal absorption via a cephalic-phase-independent and gastric-distension-independent mechanism.
进餐后，空肠腔内水和电解质的吸收增加。这种由进食引起的空肠吸收发生在正常胃肠道连续性之外的空肠段。实验模型采用清醒犬的25厘米近端空肠Thiry-Vella肠袢（n = 72次观察）来评估进食引起空肠吸收所涉及的机制，试图确定促吸收信号的来源。具体而言，我们评估了空肠对标准餐、加用阿托品进行胆碱能阻滞的标准餐、假饲餐、管饲餐以及用球囊胃扩张和管饲水的胃扩张的吸收反应。标准餐和管饲餐均能迅速、持续且显著地（P < 0.0001）增加水、钠和氯的吸收。与单独的标准餐相比，阿托品显著降低了餐后吸收反应的幅度（P < 0.05）。假饲餐、胃球囊扩张和管饲水均未改变空肠吸收。通过胃酸分泌量和胃泌素对刺激的反应来验证颈段食管操作后迷走神经的完整性。这些数据支持胆碱能通过一种不依赖头期和不依赖胃扩张的机制对进食刺激的空肠吸收进行调节。
