Figure 2. Macroscopic and microscopic aspects of healthy hamster cheek pouches (a and b) or cheek pouches from animals subjected to 5-fluorouracil (5-FU)-induced oral mucositis and that received topical applications of the vehicle HPMC (c and d) or GSNO (0.5 mM) (e and f) observed on day 14.

Oral mucositis was induced by i.p. dministration of 5-fluorouracil followed by mechanical trauma of the cheek pouch. Animals received topical applications of S-nitrosoglutathione (0.5 mM HPMC/GSNO) or vehicle only (HPMC) at 1 h prior to 5-FU and every 12 h thereafter for 14 days. Each cheek pouch was everted and photographed, and samples were removed and processed for hematoxylin and eosin staining (100× magnification). Details: in Figure 2c, macroscopic edema (arrowhead) and vasodilation (dotted line) are shown; in Figure 2d, microscopic edema (larger circled) and severe vasodilation (smaller circled) are shown. Arrow = ulcerations.