Jobin G, Cortot A, Godbillon J, Duval M, Schoeller J P, Hirtz J, Bernier J J
Br J Clin Pharmacol. 1985;19 Suppl 2(Suppl 2):97S-105S. doi: 10.1111/j.1365-2125.1985.tb02749.x.
Gastrointestinal (GI) absorption of the beta-adrenoceptor blocker metoprolol was investigated in five healthy subjects by means of an intubation method, employing a triple-lumen tube introduced into the intestine, and a twin-lumen tube in the stomach. Metoprolol was introduced into the stomach with a homogenized meal containing a nonabsorbable marker, [14C]-PEG 4000, and another marker, PEG 4000, was perfused continuously into the duodenum just below the pylorus. Samples of GI contents were collected at regular intervals over 4 h in the stomach and at two different levels in the upper small intestine. Metoprolol was not absorbed from the stomach. Approximately 60% of the amount of drug emptied from the stomach was absorbed from the duodenum; about 50% of that leaving the duodenum was absorbed from the first part of the jejunum. The delivery process was the rate-limiting factor of metoprolol absorption in these segments of the gut. Plasma concentrations reflected drug loss from the lumen and were higher in subjects exhibiting faster gastric emptying and higher absorption rates in the duodenum and jejunum. The intubation technique appeared to be a suitable method for investigating drug absorption from the GI tract in man.
通过插管法，利用插入肠道的三腔管和置于胃内的双腔管，对5名健康受试者的β-肾上腺素受体阻滞剂美托洛尔的胃肠道（GI）吸收情况进行了研究。美托洛尔与含有不可吸收标记物[14C]-聚乙二醇4000的匀浆餐一起引入胃内，另一种标记物聚乙二醇4000持续灌注到幽门下方的十二指肠。在4小时内定期收集胃内及上段小肠两个不同水平的胃肠道内容物样本。美托洛尔未从胃中吸收。从胃排空的药物约60%从十二指肠吸收；离开十二指肠的药物约50%从空肠第一部分吸收。在肠道的这些节段中，输送过程是美托洛尔吸收的限速因素。血浆浓度反映了药物从肠腔的损失，在胃排空较快且十二指肠和空肠吸收速率较高的受试者中血浆浓度更高。插管技术似乎是研究人体胃肠道药物吸收的一种合适方法。
