Objective: The management of psychiatric patients is often complicated by medical comorbidities, complex pharmacological regimens, and side effects secondary to these regimens. In the current study, it was aimed to investigate the effects and mechanism of action of trazodone on rat bladder smooth muscle contractility in vitro.
Method: Sixteen adult male Wistar albino rats were euthanized by the cervical dislocation method following ether anesthesia. Two muscle strips of 2 × 10 mm in size were prepared vertically from the bladder by opening a longitudinal incision from the neck of the bladder in the direction of the apex. The strips were tied properly and hung in the organ bath. All contraction amplitudes and frequencies were recorded. After a 45-min adaptation period, contractions were induced by applying 105 M acetylcholine (ACh) to all spontaneously contracting bladder strips. After 20 min, doses of trazodone (109 M vs 103 M) were given cumulatively. The resulting effects were recorded.
Results: The groups were compared within themselves: a significant difference was found between the initial tensions in the group with ACh-induced contractions and the tensions after the administration of trazodone at 109, 108, 107, 106, 105, 104, and 103 M doses (p < 0.0001). In the group with spontaneous contractions, a significant difference was found between the initial tensions and the tensions after the administration of trazodone at 109, 108, 105, and 104 M doses (p < 0.0001).
Conclusion: Results showed that trazodone had a significant inhibitory effect on bladder smooth muscle contractions in vitro, especially at concentrations of 104 and 103 M.