BACKGROUND/AIM: This study aimed to develop a reliable chemotherapy-induced oral mucositis (CIOM) rat model by intraperitoneally administering a single dosage of 5-fluorouracil (5-FU) combined with a chemical stimulus.

MATERIALS AND METHODS

The 5-FU dosage for CIOM development was determined by the survival rate of rats administrated 160 mg/kg, 200 mg/kg, and 240 mg/kg of 5-FU. Thirty rats were assigned to normal control (NC) and three experimental groups: i) ulcer formation without 5-FU administration (PBS/U+), ii) 5-FU administration without ulcer formation (5-FU/U-), and iii) ulcer formation after 5-FU administration (5-FU/U+). White blood cell count and weight were measured at the day of 5-FU administration (D0), ulcer formation (D2), and two days after ulcer formation (D4). The oral mucosa for histologic evaluations was obtained two (D4) and five days (D7) after ulcer formation.

RESULTS

The 5-FU dosage for CIOM development was 200 mg/kg. White blood cell count (WBC) counts and weight of rats were significantly lower in 5-FU/U- (WBC, p<0.001; weight, p=0.002) and 5-FU/U+ (WBC, p<0.001; weight, p<0.001) groups compared to those in the NC group at D4. The number of Ki-67 positive cells in the oral epithelium was lower in 5-FU/U+ group compared to that in NC (p<0.001) and PBS/U+ (p=0.047) groups at D7.

CONCLUSION

Single administration of 200 mg/kg of 5-FU combined with a chemical stimulus can lead to an immune-suppressive status, failure of weight gain, and impairment of epithelium regeneration as observed in a CIOM rat model.