Method: Male KK-Ay/TaJcl mice (KK-Ay ; CLEA, Japan) and C57BL/6JJcl mice (C57 ; CLEA) were used as animal models of diabetes and controls, respectively. We used N-Acetyl-L-Cystein (NAC) as an antioxidant until the age of 15week. These mice had free access to water and normal food with or without 1.2%NAC. Superficial circular punch biopsy wound measuring ~ 2.0mm was made in the middle of the tongue using a 1.0mm Biopsy Punch (Ft.Lauderdale, FL) by ablating the epithelial layer without damage to the underlying muscle (Nagy et al. Diabetes, 2001). The animals were euthanized at 1, 2, 3 and 4 days after the wound were made. The wound size was calculated using the formula A=LWp/4. Immunohistochemical staining was carried out using anti-eNOS (Abcam,Cambridge,UK) antibody as a primary antibody. Immunodetection kit, peroxidase was used to detect the immunoreactions according to manufacture's protocol (Elite ABC; Vector Lab. CA). The data was analyzed using ANOVA.
Result: The size of wound was significantly bigger in KK-Ay than in C57 mice at 3 days (p<0.05). Positive staining for eNOS was observed in the oral epithelial layers and blood vessel in C57 mice. Positive reaction for eNOS was faint in blood vessel in KK-Ay mice. The size of wound was significantly smaller in KK-Ay mice with NAC that those without NAC (p<0.05).
Conclusion: The results indicate that antioxidant may promote wound healing on oral mucosa in diabetes.