エタノールはモルモット単離膵管からの分泌液の陰イオン組成を変える
詳細
We reported that 1 mM of ethanol (relevant to blood level after social drinking) potentiated secretin-stimulated fluid secretion in interlobular ducts isolated from guinea-pig pancreas. In this study, we examined anion composition of the secreted fluid during the hypersecretion. Isolated ducts were cultured overnight, during which time both ends of the ducts sealed. The lumen was punctured and injected with solutions containing BCECF-dextran or ABQ-detxtran (plus Cl-NERF-dextran as ratiometric reference). Luminal pH (pHL) and luminal Cl− ([Cl−]L) were estimated by microfluorometry. Images of luminal fluorescence were obtained at 1-min intervals and the rate of fluid secretion was calculated from the increment of luminal volume. During stimulation with secretin (10 nM), the rate of fluid secretion was 2.28±0.14 nl min−1 mm−2 (per unit area of epithelium, n=5, mean±SE), pHL increased due to HCO3− secretion, and [Cl−]L steadily decreased. The net Cl− transport calculated from [Cl−]L and luminal volume was nearly zero. Ethanol (1 mM) increased secretin-stimulated fluid secretion to 4.11±0.22. pHL slightly decreased and [Cl−]L was stable in the presence of ethanol. The net Cl− transport was 0.265±0.042 nEq min−1 mm−2. The increase of fluid secretion by ethanol was almost equivalent to fluid secretion accompanying Cl− efflux. Ethanol induced Cl− secretion during secretin stimulation without affecting HCO3− secretion, which resulted in the increase of Cl− of secreted fluid from zero to about 70 mM. [J Physiol Sci. 2006;56 Suppl:S70]
