Krumbiegel P, Rolle-Kampczyk U, Liebergeld P, Herbarth O, Köbrich R
UFZ Centre for Environmental Research Leipzig-Halle, Department of Human Exposure Research and Epidemiology Leipzig, Germany.
Isotopes Environ Health Stud. 2002 Jun;38(2):65-70. doi: 10.1080/10256010208033313.
Customary 13CO2 breath tests--and also 15N urine tests--always start with an oral administration of a test substrate. The test person swallows a stable isotope labelled diagnostic agent. This technique has been used to study several pathophysiological changes in gastrointestinal organs. However, to study pathophysiological changes of the bronchial and lung epithelium, the inhalative administration of a stable isotope labelled agent appeared more suitable to us. [1-13C]Hexadecanol and [1-13C]glucose were chosen. Inhaled [1-13C]hexadecanol did not yield 13CO2 in the exhaled air, but [1-13C]glucose did. To study the practicability of the [1-13C]glucose method and the reproducibility of the results, 18 inhalation tests were performed with healthy subjects. In 6 self-tests, the optimum inhalative dose of [13C]glucose was determined to be 205 mg. Using the APS aerosol provocation system with the nebulizer 'Medic Aid' (Erich Jaeger Würzburg), a 25% aqueous solution was inhaled. Then, breath samples were collected at 15 min. intervals and analysed for 13CO2. 75-120 min after the end of inhalation a well-reproducible maximum delta13C value of 6%o over baseline (DOB) was detected for 12 healthy probands. Speculating that the pulmonary resorption of the [13C]glucose is the rate-limiting step of elimination, decompensations in the epithelium ought to be reflected in changed [1-13C]glucose resorption rates and changed 13CO2 output. Therefore, we speculate that the inhalation of suitable 13C-labelled substrates will pave the way for a new group of 13CO2 breath tests aiding investigations of specific pathophysiological changes in the pulmonary tract, such as inflammations of certain sections and decompensations of cell functions.
传统的13CO2呼气试验——以及15N尿液试验——总是从口服试验底物开始。受测者吞下一种稳定同位素标记的诊断剂。这项技术已被用于研究胃肠道器官的几种病理生理变化。然而，为了研究支气管和肺上皮的病理生理变化，对我们来说吸入一种稳定同位素标记的试剂似乎更合适。选用了[1-13C]十六醇和[1-13C]葡萄糖。吸入的[1-13C]十六醇在呼出气体中未产生13CO2，但[1-13C]葡萄糖产生了。为了研究[1-13C]葡萄糖方法的实用性和结果的可重复性，对健康受试者进行了18次吸入试验。在6次自我试验中，确定[13C]葡萄糖的最佳吸入剂量为205毫克。使用带有“Medic Aid”雾化器（埃里希·耶格·维尔茨堡公司）的APS气雾剂激发系统，吸入25%的水溶液。然后，每隔15分钟收集呼气样本并分析其中的13CO2。在12名健康受试者吸入结束后75 - 120分钟，检测到相对于基线（DOB）的最大δ13C值为6‰，且重复性良好。推测[13C]葡萄糖的肺部吸收是消除的限速步骤，上皮的代偿失调应该反映在[1-13C]葡萄糖吸收速率的改变和13CO2排出量的改变上。因此，我们推测吸入合适的13C标记底物将为一组新的13CO2呼气试验铺平道路，有助于研究呼吸道的特定病理生理变化，如某些部位的炎症和细胞功能的代偿失调。
