Drug-ll ied histological changes and its consequences on the permeability of the small intestinal mucosa. II.

The influence of chelating agents such as EDTA disodium salt and tetracycline hydrochloride, and surfactants such as sodium lauryl sulfate, sodium desoxycholate, sodium taurocholate, benzethonium chloride, polysorbate 80, HCO-50, and Pluronic F 68, upon the intestinal mucosa was investigated by measuring the apparent exsorption rate constant (K) of sulfaguanidine administered intravenously in the rat. Except Pluronic F 68, all the agents showed increase in K with concomitant histological change. Because of this histological change the permeability of sulfaguanidine from the blood vessel to the intestinal lumen was found to increase. Further, the value of K and its change with time are suggested to be usable as an indicator of the damaging effect of drugs on the intestinal mucosa.