Merritt A M, Ruckebusch Y
Department of Medical Sciences, College of Veterinary Medicine, University of Florida, Gainesville 32610.
Dig Dis Sci. 1988 Jan;33(1):60-6. doi: 10.1007/BF01536632.
Antroduodenal myoelectrical activity and duodenal digesta flow rate in young cattle were assessed by implanted nichrome wire electrodes and reentrant duodenal cannulation with interposed flow-meter. In addition, a small glass electrode was inserted through a duodenal cannula to continuously measure the pH of duodenal contents. When eating only hay ad libitum, the duodenal myoelectrical activity showed the usual migrating myoelectrical complex (MMC) pattern. Duodenal contents pH rose sharply at the end of a period of repetitive spike activity (RSA), or phase III, from pH less than 2 to greater than 5 and remained high through most of the subsequent period of no spike activity (NSA), or phase I, during which there was no antral spiking and no flow of duodenal contents. Feeding milk (pH 6.5) caused a marked increase in antroduodenal spike activity and intraduodenal flow rate, with a concomitant rapid rise in duodenal contents pH from 1.8 +/- 0.3 (SEM) to 5.0 +/- 0.2 which then slowly declined over the next few hours. Within 5 min after the administration of the alpha 2-adrenergic agonist xylazine (25 and 50 micrograms/kg intramuscular), there was a significant increase (P less than 0.05) in antroduodenal spike frequency and a concomitant marked drop in intraduodenal flow rate with a sustained low pH of intraduodenal contents. The results suggest that: (1) continuous measurement of proximal duodenal pH adds a useful dimension to documenting relationships between antroduodenal myoelectrical activity and duodenal digesta flow rate; and (2) increased spike activity in the antroduodenal region does not necessarily indicate an increased duodenal flow rate is occurring.
通过植入镍铬丝电极和带有插入式流量计的折返式十二指肠插管，对幼牛的十二指肠肌电活动和十二指肠食糜流速进行了评估。此外，通过十二指肠插管插入一个小玻璃电极，以连续测量十二指肠内容物的pH值。当随意采食干草时，十二指肠肌电活动呈现出常见的移行性肌电复合波（MMC）模式。在重复棘波活动（RSA）期或第三阶段结束时，十二指肠内容物pH值从小于2急剧升至大于5，并在随后大部分无棘波活动（NSA）期或第一阶段保持高位，在此期间胃窦无棘波活动且十二指肠内容物无流动。饲喂牛奶（pH 6.5）导致胃十二指肠棘波活动和十二指肠内流速显著增加，同时十二指肠内容物pH值从1.8±0.3（SEM）迅速升至5.0±0.2，然后在接下来的几个小时内缓慢下降。在肌内注射α2 - 肾上腺素能激动剂赛拉嗪（25和50微克/千克）后5分钟内，胃十二指肠棘波频率显著增加（P＜0.05），同时十二指肠内流速显著下降，十二指肠内容物pH值持续较低。结果表明：（1）连续测量十二指肠近端pH值为记录胃十二指肠肌电活动与十二指肠食糜流速之间的关系增加了一个有用的维度；（2）胃十二指肠区域棘波活动增加不一定表明十二指肠流速增加。
