Physical, chemical, and immunohistochemical investigation of the damage to salivary glands in a model of intoxication with aluminium citrate.

Aluminum absorption leads to deposits in several tissues. In this study, we have investigated, to our knowledge for the first time, aluminum deposition in the salivary glands in addition to the resultant cellular changes in the parotid and submandibular salivary glands in a model of chronic intoxication with aluminum citrate in rats. Aluminum deposits were observed in the parotid and submandibular glands. Immunohistochemical evaluation of cytokeratin-18 revealed a decreased expression in the parotid gland with no changes in the submandibular gland. A decreased expression of α-smooth muscle actin was observed in the myoepithelial cells of both glands. The expression of metallothionein I and II (MT-I/II), a group of metal-binding proteins, which are useful indicators for detecting physiological responses to metal exposure, was higher in both glands. In conclusion, we have shown that at a certain time and quantity of dosage, aluminum citrate promotes aluminum deposition in the parotid and submandibular glands, leads to an increased expression of MT-I/II in both the glands, damages the cytoskeleton of the myoepithelial cells in both glands, and damages the cytoskeleton of the acinar/ductal cells of the parotid glands, with the submandibular glands showing resistance to the toxicity of the latter.