CHRONIC SENNOSIDE TREATMENT DOES NOT CAUSE HABITUATION AND SECONDARY HYPERALDOSTERONISM IN RATS

Rats were treated with sennosides (6 x 10, 6 x 40 or 2 x 30 mg/kg week ly) or with danthron (6 x 500 mg/kg weekly) for 6 months. The laxative effect as measured by faecal wet weight during the first 10 h after t reatment increased 3- to 4-fold by the higher sennoside doses (daily o r intermittently) and 1- to 3-fold by danthron. The low sennoside dose had no measurable effect except on the 1st day (2 fold) compared with the control group. Mean faecal water content increased from 53% (cont rols) to 66-79% in rats treated with high sennoside doses and to 57 (1 st day) -69% in danthron-treated rats. Serum aldosterone levels and mu cosal Na+-K+-ATPase activities in the small intestine and colon did no t change with treatment. There were no signs of habituation or seconda ry hyperaldosteronism due to sennosides or danthron in spite of chroni c diarrhoea over 6 months.