Effects of Nicotine on the Submandibular Gland in Rats

To evaluate the histopathologic and immunohistochemical effects of systemic use of nicotine on the submandibular glands.

We investigated the effects of nicotine on apoptosis and angiogenesis. Twenty adult Sprague-Dawley rats were divided into 2 groups: nicotine (n = 10) and controls (n = 10). The rats of the nicotine group were administered 2 mg/kg nicotine sulphate for 28 days. All animals were sacrified at the end of the study, and submandibular samples were removed and prepared for histologic examination. Proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and Bcl-2 antibodies were used for immunohistochemical examination.

In the group treated with nicotine, we observed degeneration in serous cells and striated duct cells, dilation and hemorrhage of blood vessels in the stromal area, and an increase of fibrous tissue and edema. An increase was observed in the number of PCNA-positive cells as compared to in the controls. VEGF expression was found to be positive in vascular endothelial cells and inflammatory cells around the excretory ducts in the stromal area. The duct cells are immunoreactive to Bcl-2 antibody. Apoptosis was observed in some cells of the serous glands and ducts.

Nicotine administration in this study induced apoptosis with salivary gland cell proliferation and is thought to have affected angiogenesis.