Action of lithium carbonate on parotid acini

Abstract

Objective: The aim of this study is to quantify the number (N) and to measure the volume (V) of acinar cells of parotid gland. The size and the mass of parotid glands were also assessed in rats subjected to chronic lithium carbonate treatment, mimicking the treatment paradigm of bipolar disorder.Design: Twenty-five male Wistar rats received intra-peritoneal injections of either saline (n=11) or lithium carbonate (60 mg/kg body weight) for 51 days. The parotid glands of each animal were removed, weighed, measured and processed, and the histological sections stained with hematoxylinand eosin, from which the N and V were quantified. Statistical analysis was performed using Student's t test.Results: It was found that with the use of lithium, there was a statistically significant increase in the gland size (1.00 ± 0.20 cm) and mass (150.71 ± 73.95 mg) when compared to the control (0 80 cm ± 0.17 and 108.93 ± 17.00 mg, respectively) (p<0.05). The number of acinar cells and acinar volume was not statistically different when compared control and lithium. Conclusion:Lithium carbonate may not modify the cell number and volume, indicating that lithium carbonate does not cause changes in morphometric glandular parenchyma. Moreover, the increase inglandular size and mass might suggest that stroma is swollen and this could result in hyposalivation.