Scott R B, Strasberg S M, El-Sharkawy T Y, Diamant N E
J Clin Invest. 1983 Mar;71(3):644-54. doi: 10.1172/jci110811.
The purpose of this study was to correlate the fasting enterohepatic circulation (EHC) of bile acids with the migrating myoelectric complex. Four dogs were surgically provided with a functional cholecystectomy, a duodenal cannula for direct vision cannulation of the common bile duct, and 12 bipolar electrodes implanted from stomach to terminal ileum. Bile was collected in equal-volume, timed aliquots over 6 to 10 h. Aliquots were sampled and either returned to the duodenum for study of the intact EHC, or collected and retained in order to study the time course of the bile acid pool washout. In the washout experiments boluses of radiolabeled taurocholic acid were instilled into the duodenum before and after duodenal phase III of the migrating motor or myoelectric complex (MMC). In another group of experiments the bile acid pool was washed out and during a continuous duodenal infusion of taurocholic acid bile was collected to study the pattern of hepatic secretion.
(a) In all experiments, a single broad peak of bile flow and bile acid secretion occurred at 35-55% of the MMC migration time. At this time the MMC had migrated to a point 70-85% of the distance along the small intestine. (b) During bile acid pool washout the peak of bile flow and bile acid secretion occurred with the distal migration of the first MMC and then bile flow and bile acid secretion rates decreased to a minimum and stabilized. (c) In bile acid pool washout experiments the radiolabeled bile acids instilled into the duodenum prior to duodenal phase III were secreted and peaked with peak endogenous bile acid secretion. The secretion of radiolabeled bile acids instilled into the duodenum after duodenal phase III was delayed until the subsequent cycle of the MMC. 88% of the bile acid pool collected over 6 h was secreted during the distal migration of the first MMC (2.4 +/- 0.4 h). (d) After bile acid pool washout and during continuous duodenal infusion of taurocholic acid, hepatic bile flow and bile acid secretion continued to fluctuate with the same pattern observed with the EHC intact.
(a) In the fasting state, the transport of intestinal bile acids to the liver is pulsatile rather than continuous and is determined by the MMC. Maximum hepatic secretion occurs when phase III of the MMC propels the intraluminal bile acid pool to its site of absorption in the distal small bowel. (b) The "housekeeping" action of the MMC is very efficient and clears 88% of the 6-h washout bile acid pool in one pass.
本研究的目的是将胆汁酸的空腹肠肝循环（EHC）与移行性肌电复合波相关联。对4只狗进行手术，使其功能性胆囊切除，插入十二指肠插管以便直接观察胆总管插管情况，并在从胃到回肠末端植入12个双极电极。在6至10小时内按等体积、定时收集胆汁。对收集的等分试样进行采样，要么返回十二指肠以研究完整的EHC，要么收集并留存以研究胆汁酸池清除的时间进程。在清除实验中，在移行运动或肌电复合波（MMC）的十二指肠第三相之前和之后，将放射性标记的牛磺胆酸注入十二指肠。在另一组实验中，清除胆汁酸池，并在持续十二指肠输注牛磺胆酸期间收集胆汁以研究肝脏分泌模式。
（a）在所有实验中，胆汁流量和胆汁酸分泌的单个宽峰出现在MMC移行时间的35 - 55%。此时MMC已移行至沿小肠距离的70 - 85%处。（b）在胆汁酸池清除期间，胆汁流量和胆汁酸分泌的峰值随着第一个MMC的远端移行而出现，然后胆汁流量和胆汁酸分泌率降至最低并稳定下来。（c）在胆汁酸池清除实验中，在十二指肠第三相之前注入十二指肠的放射性标记胆汁酸被分泌出来，并与内源性胆汁酸分泌峰值同时达到高峰。在十二指肠第三相之后注入十二指肠的放射性标记胆汁酸的分泌延迟至MMC的后续周期。在第一个MMC远端移行期间（2.4±0.4小时），6小时内收集的胆汁酸池的88%被分泌。（d）在胆汁酸池清除后并在持续十二指肠输注牛磺胆酸期间，肝脏胆汁流量和胆汁酸分泌继续以与完整EHC时观察到的相同模式波动。
（a）在空腹状态下，肠道胆汁酸向肝脏的转运是脉动性的而非连续性的，并且由MMC决定。当MMC的第三相将肠腔内胆汁酸池推进到其在远端小肠的吸收部位时，肝脏分泌达到最大值。（b）MMC的“清理”作用非常有效，一次就能清除6小时清除的胆汁酸池的88%。
