Effects of Antidepressants and Pilocarpine on Rat Parotid Glands

Objectives: The aim of this study was to evaluate the effects of antidepressants and pilocarpine on rat parotid glands and on the behavior of myoepithelial cells.

Methods: Ninety male Wistar rats were allocated to nine groups. Control groups received saline during 30 (C30) and 60 days (C60). Other control group (Pilo) received topic pilocarpine during 60 days. Experimental groups received Prozac^® (P30) and Efexor^® (E30) during 30 days. Others experimental groups received Prozac^® (PS60) and Efexor^® (ES60) associated with saline, and Prozac^® (PP60) and Efexor^® (EP60) associated with pilocarpine during 60 days. The stimulated salivary flow rate (SSFR) was obtained by using the gravimetric method. After the animals were killed, parotid glands were removed and their mass (M) and size (S) were determined. The specimens were processed and stereological analysis revealed cell volume (CV). The immunohistochemical expression of calponin and PCNA on myoepithelial and parenchymal cells was evaluated. The normality and homogeneity of variances of the studied variables were tested by the Kolmogorov-Smirnov and Levene tests, respectively. ANOVA, Multiple Comparisons Tukey HSD and Games-Howell tests were applied to detect differences among the groups. All the statistical tests were performed at a level of significance of 5% (p<0.05).

Results: Antidepressants chronic use induced an increase in the S of the parotid glands and in the CV of acinar cells, and a decrease in the SSFR (p<0.05). Group EP60 presented a significant increase (p=0.0214) in SSFR when compared with group ES60. The groups treated with antidepressants showed an increase in the number of positive staining cells for PCNA and calponin when compared to the controls (p<0.05).

Conclusion: Pilocarpine showed significant secretagogue action in the treatment of hyposalivation induced by antidepressants chronic use.

This study was supported by CNPq (grant 474790/2004-5).