Do the anti-reproductive effects of fluoxetine involve changes in seminal vesicle contraction? A preclinical study

Abstract

Fluoxetine treatment has been found to induce delayed ejaculation in humans. This effect may result from fluoxetine's direct action on the smooth muscle of the seminal vesicle, potentially hindering its motor activity and seminal emission during ejaculation. Therefore, this study aimed to assess the effects of in vitro fluoxetine on contractions of rat seminal vesicle induced by KCl or autonomic agonists noradrenaline or carbachol. The rat seminal vesicle was isolated and mounted in an organ bath setup. The tissues were subjected to concentrationresponse curves for KCl, noradrenaline, or carbachol in the absence or presence of fluoxetine (1, 3, or 10 µM) pre-incubated for 40 minutes. Concentration-response curves for KCl in the presence of 3 µM fluoxetine were also generated using a normal nutrient solution, followed by the cumulative addition of CaCl2, or using a nutrient solution with a high concentration of CaCl2. In vitro fluoxetine reduced the maximal effect of KCl, noradrenaline and carbachol on rat seminal vesicle. The effects of fluoxetine on KCl-induced seminal vesicle contractions were reversed by adding exogenous calcium or attenuated when the tissues were bathed with nutrient solution containing a high concentration of this ion. In conclusion, fluoxetine negatively affects the contractility of rat seminal vesicle.