To determine the early-stage effects of 5-fluorouracil (5-FU) on the histology of the submandibular gland. Materials and methods: The study included 30 New Zealand rabbits. They were divided into 3 groups. No drugs were administered to group 1 (control group), and 5-FU was administered for 5 days to group 2 and for 10 days to group 3. Submandibular gland excision was then performed. Histopathological examination was performed with hematoxylin-eosin staining, apoptosis was determined based on TUNEL staining, and cell proliferation was examined using the PCNA antibody. Results: While no granular change was seen in group 1, granular change was observed in the acinar cell cytoplasm in 5 rabbits in group 2 and in 5 rabbits in group 3 (P < 0.05). The rate of apoptosis in the acinar and ductal cells was higher in group 3 than in groups 1 and 2, according to TUNEL staining (P < 0.05). While no cellular proliferation in the acinar cells was observed with PCNA staining in any of the groups, there was a statistically significant difference in group 3 in ductal cellular proliferation, as compared to groups 1 and 2 (P < 0.05). Conclusion: Toxic effects of 5-FU were observed after 10 days. We suggest that a standard animal model can be developed based on group 3 results. We also think that drug trials concerned with protecting the salivary gland from the effects of chemotherapy can be conducted based on this model.

To determine the early-stage effects of 5-fluorouracil (5-FU) on the histology of the submandibular gland. Materials and methods: The study included 30 New Zealand rabbits. They were divided into 3 groups. No drugs were administered to group 1 (control group), and 5-FU was administered for 5 days to group 2 and for 10 days to group 3. Submandibular gland excision was then performed. Histopathological examination was performed with hematoxylin-eosin staining, apoptosis was determined based on TUNEL staining, and cell proliferation was examined using the PCNA antibody. Results: While no granular change was seen in group 1, granular change was observed in the acinar cell cytoplasm in 5 rabbits in group 2 and in 5 rabbits in group 3 (P < 0.05). The rate of apoptosis in the acinar and ductal cells was higher in group 3 than in groups 1 and 2, according to TUNEL staining (P < 0.05). While no cellular proliferation in the acinar cells was observed with PCNA staining in any of the groups, there was a statistically significant difference in group 3 in ductal cellular proliferation, as compared to groups 1 and 2 (P < 0.05). Conclusion: Toxic effects of 5-FU were observed after 10 days. We suggest that a standard animal model can be developed based on group 3 results. We also think that drug trials concerned with protecting the salivary gland from the effects of chemotherapy can be conducted based on this model.