Lambert G P, Chang R T, Joensen D, Shi X, Summers R W, Schedl H P, Gisolfi C V
Department of Physiology, University of Iowa, Iowa City, USA.
Int J Sports Med. 1996 Jan;17(1):48-55. doi: 10.1055/s-2007-972807.
Because fluid absorption values derived from intestinal perfusion may not represent intestinal absorption of the same solution following its oral ingestion, the present study measured intestinal absorption following oral ingestion of a beverage. To do so required the simultaneous determination of gastric emptying. Seven males positioned a nasogastric tube in the gastric antrum and a multilumen tube in the duodenum under fluoroscopic guidance. Gastric emptying (GE) and intestinal water flux (WF) were measured during 85 min of cycle exercise at 60.6 +/- 3.7% VO2max (x +/- SE) in a 22 degrees C environment. Subjects ingested a total of 23 ml.kg-1 body weight (2005 +/- 187 ml) of a 6% isotonic carbohydrate-electrolyte solution by drinking 396 +/- 34 ml 5 min prior to exercise followed by 198 +/- 17 ml every 10 min during exercise. Mean stomach volume (312 +/- 80 ml) and GE (19.7 +/- 2.0 ml.min-1) did not change significantly after the initial 35 min equilibration period. Mean WF during oral ingestion of the solution (19.5 +/- 2.6 ml.cm-1.h-1) did not differ significantly from mean WF (16.4 +/- 1.9 ml.cm-1.h-1) during perfusion of the same solution directly into the duodenum at a rate equal to each subject's GE rate. Total solute flux (mmol.cm-1.h-1) was not different between drinking (4.1 +/- 1.3) and infusion (3.8 +/- 1.0) trials, nor were the changes in plasma volume. Urine production immediately following the exercise bout was unchanged between drinking (89.1 +/- 27.5 ml) and perfusion (88.5 +/- 24.2) experiments. These data indicate that: 1) relatively constant stomach volumes can be maintained over a prolonged period of time and can produce relatively constant GE rates, and 2) intestinal absorption of an isotonic carbohydrate-electrolyte beverage can be accurately determined by a modified segmental perfusion technique employing ingestion rather than intestinal perfusion.
由于肠道灌注得出的液体吸收值可能无法代表口服相同溶液后的肠道吸收情况，因此本研究测量了口服一种饮料后的肠道吸收。为此需要同时测定胃排空。七名男性在荧光镜引导下将一根鼻胃管置于胃窦，将一根多腔管置于十二指肠。在22摄氏度环境中，以60.6±3.7%最大摄氧量（x±SE）进行85分钟的循环运动期间，测量胃排空（GE）和肠道水通量（WF）。受试者共摄入23毫升·千克-1体重（2005±187毫升）的6%等渗碳水化合物-电解质溶液，运动前5分钟饮用396±34毫升，运动期间每10分钟饮用198±17毫升。在最初35分钟的平衡期后，平均胃容积（312±80毫升）和GE（19.7±2.0毫升·分钟-1）没有显著变化。口服溶液期间的平均WF（19.5±2.6毫升·厘米-1·小时-1）与以每个受试者的GE速率将相同溶液直接灌注到十二指肠期间的平均WF（16.4±1.9毫升·厘米-1·小时-1）相比，差异不显著。饮用（4.1±1.3）和输注（3.8±1.0）试验之间的总溶质通量（毫摩尔·厘米-1·小时-1）没有差异，血浆量的变化也没有差异。运动后立即产生的尿量在饮用（89.1±27.5毫升）和灌注（88.5±24.2）实验之间没有变化。这些数据表明：1）可以在较长时间内维持相对恒定的胃容积，并能产生相对恒定的GE速率；2）采用口服而非肠道灌注的改良节段灌注技术，可以准确测定等渗碳水化合物-电解质饮料的肠道吸收情况。
