Sclerotic effect of bleomycin on the submandibular gland: an experimental model.

Objectives: To evaluate the sclerotic effect of bleomycin on the submandibular gland histopathologically and assess it as a possible alternative therapy for sialorrhea.

Methods: An experimental model was designed and 18 New Zealand white rabbits were used. The rabbits were divided into two groups: a bleomycin group (n=9) and a sham group (n=9). The submandibular glands of the bleomycin group were injected with 0.3 ml bleomycin (3mg/ml) while the sham group received 0.3 ml saline. Four weeks after the procedure, the glands were removed. Histopathological studies including hematoxylin-eosin and Masson's trichrome stain were carried out. The glands were evaluated for tissue inflammation, fibrosis, edema, lipomatosis, atrophy and congestion. To investigate apoptosis, terminal deoxynucleotidyl transferase (TdT)-mediated digoxigenin-11-dUTP nick-end labeling (TUNEL) immunohistochemical staining was used.

Results: In the group injected with bleomycin, inflammation (n=8), edema (n=4), fibrosis (n=3), congestion (n=4) and lipomatosis (n=7) were observed. In the sham group, only lipomatosis was observed. The TUNEL assay results were 5.06 ± 1.18 (p<0.05) for acinar cells and 8.46 ± 0.82 (p<0.05) for ductal cells in the bleomycin group. This was significantly different from the results in the sham group.

Conclusions: Apoptosis, inflammation, fibrosis, edema, lipomatosis and congestion were observed in the ductal and acinar cells of the bleomycin group. Bleomycin may be an alternative treatment for sialorrhea cases. However, more research is needed.