Stimulation of Na Absorption by the Antiasthmatic Kampo Drug Saiboku-To in Cultured Airway Epithelium

To study the effect of the Kampo drug Saiboku-to (TJ-96) on ion transport function of airway epithelial cells, we studied bioelectric properties of cultured tracheal epithelium from dogs under short-circuit conditions in vitro. Addition of TJ-96 (1 mg/ml) to the mucosal solution of the Ussing chamber increased the epithelial short-circuit current (SCC) from 6.5 ± 0.7 to 11.4 ± 1.6μA/cm2 (P < 0.001). This effect was dose-dependent, with the maximal increase from the baseline value and the concentration required to produce a half-maximal effect (EC50) being 70.5 ± 12.6% (P <