G. Nijs et al., CONVENTIONALIZATION OF GERM-FREE RATS REVERSES THE DISABILITY OF RHEIN ANTHRONE TO INDUCE LAXATION, European journal of pharmacology, 239(1-3), 1993, pp. 241-243
This study shows that rhein anthrone has no laxative potency in germ-f
ree rats because after intracaecal administration of a dose of 50 mg/k
g the large intestine transit exceeded 240 min. The time course of the
laxative potency of rhein anthrone injected intracaecally was evaluat
ed after peroral inoculation of germ-free rats with the caecal content
s of conventional rats. Large intestine transit was measured at consec
utive periods, on days 0, 1, 2, 3 and 5 after peroral inoculation. It
appeared that 1 day after peroral inoculation the laxative potency of
rhein anthrone was already established (large intestinal transit < 10
min) and laxation remained on the following days (days 2, 3 and 5). We
conclude that rhein anthrone is inactive in germ-free rats and acquir
es laxative potency after peroral inoculation of germ-free rats with c
aecal contents of conventional rats.