Effects of Hange-shashin-to on cholera toxin-induced fluid secretion in the small intestine of rats

Abstract

The effects of Hange-shashin-to (TJ-14) on cholera toxin-induced intestinal fluid secretion were studied to elucidate the mechanism by which this kampo medicine manifests antidiarrheal effects. TJ-14 suppressed the intestinal fluid secretion induced by cholera toxin (1 μg/rat) in a dose- dependent manner at doses between 125 and 1000 mg/kg. It also inhibited the luminal prostaglandin E2 (PGE2) level. On the other hand, serotonin (5-HT) release was not affected by TJ-14. Subcutaneous injection of indomethacin at 10 mg/kg or ondansetron at 100 kg significantly suppressed intestinal secretion. The luminal PGE22 level was also inhibited by indomethacin (10 mg]kg, s.c.). TJ-14, even at 102-4 g/ml, had little effect on the phasic contraction of isolated guinea pig ileum induced by 5-HT (2 x 102-6 g/ml), while ondansetron suppressed the phasic contraction caused by 5-HT. These results indicate that TJ-14 is useful in suppressing cholera toxin- stimulated intestinal fluid secretion, and that this effect is partially due to its suppressive action on the PGE2 level.