Ultrastructural and biochemical analysis of the effects of alendronate on salivary glands of young rats Taı ´s C. Oliveira, Vivian Bradaschia-Correa, Juliana R. Castro, Alyne Simo ˜ es, Victor E. Arana-Chavez * Department of Biomaterials and Oral Biology, School of Dentistry, University of Sa ˜o Paulo, Brazil 1. Introduction As other internal cavities in the body, the oral cavity has its surface lined by a mucous membrane to which salivary glands, a group of exocrine glands, flow their secretions for lubrication purposes. Due to its fluid characteristics, saliva is essential to preserve the integrity of teeth and oral soft tissues. In the oral cavity, however, saliva plays a more complex role than only lubrication. Normal salivary function is important for health maintenance. The decrease in salivary flow and changes in composition of saliva yield an imbalance that is manifested clinically by increased incidence of caries, sus- ceptibility to oral candidiasis, xerostomia (dry mouth), difficulty speaking, chewing, swallowing, altered taste and halitosis. 1 a r c h i v e s o f o r a l b i o l o g y 5 9 ( 2 0 1 4 ) 1 3 0 7 – 1 3 1 1 a r t i c l e i n f o Article history: Accepted 26 July 2014 Keywords: Parotid gland Submandibular gland Alendronate Amylase Rat a b s t r a c t Introduction: The bisphosphonates are drugs known by their antiresorptive potency and are widely prescribed for treating and preventing osteoporosis. In the past years the employ- ment of this class of drugs had spread to other pathologies, and it is being prescribed to patients in a wide range of ages. Some adverse effects of bisphosphonate treatment have been highlighted recently, however, little is known about its potential side effects in salivary glands. Methods: Newborn rats received daily doses of 2.5 mg/kg/day of sodium alendronate during 30 days. On the thirtieth day the animals were stimulated with pilocarpine and their parotid and submandibular glands were collected, fixed and embedded for histological and ultra- structural analysis. Some glands were collected for analysis of protein content and amylase activity. Results: At light microscopy, the alendronate-treated animals presented an accumulation of secretion granules in their cytoplasm, which was confirmed by the ultrastructural exami- nation. Biochemical analysis revealed an increase in total protein content and decreased amylase levels of both glands in the alendronate-treated animals in relation to the control. Conclusion: Based on the current findings, alendronate is probably interfering in secretory pathways of parotid and submandibular glands. # 2014 Elsevier Ltd. All rights reserved. * Corresponding author at: Department of Biomaterials and Oral Biology, University of Sa ˜o Paulo School of Dentistry, Avenida Professor Lineu Prestes 2227, 05508-000 Sa ˜o Paulo, SP, Brazil. Tel.: +55 11 30917840; fax: +55 11 30917840. E-mail address: vearana@usp.br (V.E. Arana-Chavez). Available online at www.sciencedirect.com ScienceDirect journal homepage: http://www.elsevier.com/locate/aob http://dx.doi.org/10.1016/j.archoralbio.2014.07.020 0003–9969/# 2014 Elsevier Ltd. All rights reserved.