Characterization of mitomycin C-induced gastrointestinal damage: changes in the gastric absorption of drugs in rats.

The effect of mitomycin C (MMC) pre-administration intravenously on the absorption of drugs from rat stomach has been examined by means of the in-situ loop technique. 48 h after the MMC-treatment, the absorption of salicylic acid, aspirin and sulphanilic acid was not influenced but that of sulphanilamide was significantly increased compared with the control. At 96 h, a differential effect of MMC on the absorption of each drug was seen: the absorption of weakly acidic drugs was significantly decreased while that of bases and strong sulphonic acid increased. The decreased absorption of salicylic acid and aspirin correlated with the reduced gastric mucosal blood flow. At 96 h there were severe haemorrhagic lesions in the gastric mucosae. The increase in absorption of poorly absorbed drugs could be ascribed to the increased permeability of the blood-gastric epithelium barrier as was evidenced by leakage of Evans Blue.