Análise do efeito de inibidores de fosfodiesterase do tipo 5 em parâmetros urodinâmicos de camundongos utilizando modelo experimental de hiperatividade detrusora

Abstract

Erectile dysfunction and Lower Urinary Tract Symptoms (LUTS) secondary to Benign Prostate Hyperplasia (BPH) are two conditions with high prevalence in men, especially in older age groups. After demonstration of similar pathophysiological mechanisms, several randomized controlled trials showed improvement in urinary symptoms with the use of Phosphodyesterase 5 Inhibitors (PDE5-I). We studied Cystometric parameters of mice in an experimental model of detrusor overactivity secondary to chronic depletion of NO by administration of Nω-nitro-L-arginine methil esther hidrocrolide (L –NAME) in animals treated with Sildenafil, Tadalafil and Vardenafil. Thirty-five mice were divided into 5 groups of 6 animals and one group of 5 (DTAD - Tadalafil diluent). All animals were treated for a period of 4 weeks. The groups received standard food and water, and one group received no further treatment (control). The other groups were treated with L-NAME alone, L- NAME + Sildenafil, L- NAME + Vardenafil, L -NAME + Tadalafil and L-NAME + DTAD. After treatment, the animals were anesthetized and cystometry was performed. The analysis of variance was used for evaluation of results. The group treated with sildenafil had fewer NVCs ( 2.16 ± 1.60 ) and lower BP ( 21.64 ± 4.63 ) , TP ( 22.56 ± 5.37 ) and MF ( 1.23 ± 0.26 ) compared to L -NAME . The group treated with Vardenafil also showed fewer NVCs (2.66 ± 2.06) and lower BP (21.87 ± 5.86) and MF (1.24 ± 0.30) compared to L -NAME. The group treated with Tadalafil had less NVCs (3.16 ± 1.47) and lower BP (20.61 ± 5.50), TP (25.45 ± 8.84) and MF (1.14 ± 0.31) relative to the L- NAME. The DTAD solution (xanthan gum and mannitol), used to optimize the dilution of Tadalafil, had only one parameter with significant difference compared to L –NAME, the MF (1.28 ± 0.16). There was no significant difference between Sildenafil, Tadalafil and Vardenafil groups in any parameter evaluated. The PDE5-Is were effective in protecting animal bladder from deleterious effects caused by chronic depletion of NO by administration of L -NAME. There was no superiority of any drug tested against another.