Chest
Mechanisms of Gastric Juice-Induced Hyperpermeability of the Cultured Human Tracheal Epithelium
Section snippets
Collection of Gastric Juice
Gastric juice was collected from 46 patients (mean age, 33 years; range, 18 to 42 years) who complained of GI symptoms such as stomach pain, nausea, or heartburn, and were judged to have no overt gastroduodenal disease with endoscopic examination. The patients had fasted for more than 12 h and had not taken antacid drugs, histamine H2-blockers, or proton pump inhibitors before the endoscopic examination. A flexible fiberoptic gastroscope (9.8 mm outer diameter; GIF-XK 200; Olympus; Tokyo,
Composition of the Gastric Juice
Table 1 shows the physicochemical properties and enzymatic analysis of the gastric juice that was exposed to the cultured human tracheal epithelial cells. The pH of the gastric juice was as low as 1.77±0.21 and the gastric juice contained a significant amount of proteolytic enzyme, pepsin.
Effects of pH of the Gastric Juice on G
Figure 1 shows time course changes in G induced by the crude gastric juice (pH, 1.77±0.21) and gastric juice adjusted to a pH of 2.8, a pH of 4.0, and a pH of 7.4 in the cultured tracheal epithelium. The pH of
Discussion
The cultures of airway epithelium used were poorly differentiated with a baseline short-circuit current less than 10% that of human bronchial epithelium.18 Ultrastructurally, they were highly flattened and lacked both cilia and secretory granules. The culture conditions developed by Yamaya et al7 produce human tracheal epithelial cells little different from the native tissue in their ultrastructure and electrical properties.19 By using the cultured human tracheal epithelium, we showed that
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