Time-course study of gastric damages in rats by anti-inflammatory drugs using a gastroscope and its quantification

Time-course studies on gastric damages in rats caused by nonsteroidal anti-inflammatory drugs (NSAIDs) were performed using a gastroscope, and the readings were quantified to obtain the Congestion-Hemorrhage Index (CHI) for evaluating the potencies of the damaging properties of NSAID. The correlation between CHI and Ulcer Index (UI), the quantified value obtained by the conventional methods, was highly significant at 6 and 24 hr after forced oral administration of NSAID. The peak CHIs of aspirin (300 mg/kg), indomethacin (60 mg/kg), mefenamic acid (300 mg/kg) and fenoprofen calcium (300 mg/kg) appeared approximately 24 hr after a single forced oral administration of drugs. Thus, it was suggested that an observation at 24 hr in addition to one at 6 to 7 hr might be necessary for the examination of damaged gastric mucosa. Under the present experimental conditions, fenoprofen calcium caused the greatest damages on gastric mucosa among the four NSAIDs. Mefenamic acid showed the least damaging potency on gastric mucosa, having a smaller CHI than that of aspirin. Indomethacin possessed a stronger damaging property than aspirin.