Influence of sildenafil on blood oxygen saturation of the obstructed bladder

Abstract

BackgroundBlood oxygen saturation (BOS) is decreased in a low-compliant, overactive obstructed bladder. The objective of this study is to determine the effect of Sildenafil (SC) on bladder function and BOS) in an in vivo animal model of bladder outlet obstruction.MethodsThirty-two guinea pigs; sham operated (n = 8), sham operated + SC (n = 8), urethrally obstructed (n = 8) and urethrally obstructed + SC (n = 8) were studied during an 8 week period. BOS of the bladder wall was measured by differential path-length spectroscopy (DPS) before obstruction, at day 0, and at week 8. The bladder function was evaluated by urodynamic studies every week.ResultsBefore surgery and after sham operation all study parameters were comparable. After sham operation, bladder function and BOS did not change. In the obstructed group the urodynamic parameters were deteriorated and BOS was decreased. In the group obstruction + SC, bladder compliance remained normal and overactivity occurred only sporadic. BOS remained unchanged compared to the sham group and was significantly higher compared to the obstruction group.ConclusionsIn an obstructed bladder the loss of bladder function is accompanied by a significant decrease in BOS. Treatment of obstructed bladders with SC yields a situation of high saturation, high bladder compliance and almost no overactivity. Maintaining the microcirculation of the bladder wall might result in better bladder performance without significant loss of bladder function. Measurement of BOS and interventions focussing on tissue microcirculation may have a place in the evaluation / treatment of various bladder dysfunctions.

Effects of the phosphodiesterase 5 inhibitor Tadalafil on bladder function in a rat model of partial bladder outlet obstruction

“…In the present study, bladder blood flow was protected by oral administration of Tadalafil. This is consistent with previous findings that acute treatment with another PDE5 inhibitor, Vardenafil, improves bladder oxygenation in SHR and that repeated treatment with Sildenafil improves blood oxygen saturation in a pig model of BOO . Our results suggest that Tadalafil, like Vardenafil and Sildenafil, has the potential to increase the blood supply and so improve oxygenation in several LUT structures.…”

“…The beneficial actions of Tadalafil in LUT tissues may not be solely attributable to its vascular effects, because this drug also affects not only tissue perfusion but also smooth muscle relaxation, smooth muscle and endothelial cell proliferation, fibrosis, and afferent nerve activity . Therefore further studies are needed for a full understanding the mode of action of Tadalafil.…”

Lower urinary tract symptoms/benign prostatic hypertrophy and vascular function: Role of the nitric oxide–phosphodiesterase type 5–cyclic guanosine 3′,5′‐monophosphate pathway

“…137 In an obstructed bladder of a guinea pig, the PDE5 inhibitor sildenafil improved the loss of bladder function accompanied by a significant decrease in blood oxygen saturation through an increase in bladder blood flow. 138 Tadalafil suppressed the decrease in bladder blood flow and impairment of bladder function in a rat partial bladder outlet obstruction model. 139 In humans also, a single administration of PDE5 inhibitors, sildenafil, valdenafil and tadalafil, significantly increased prostate blood flow detected by power Doppler ultrasound in patients with BPH, patients with prostate-specific antigen level of >4 ng/mL and healthy individuals.…”

“…Acute administration of the PDE5 inhibitor, valdenafil, restored hypoxia and caused relaxation in the bladder from a spontaneously hypertensive rat . In an obstructed bladder of a guinea pig, the PDE5 inhibitor sildenafil improved the loss of bladder function accompanied by a significant decrease in blood oxygen saturation through an increase in bladder blood flow . Tadalafil suppressed the decrease in bladder blood flow and impairment of bladder function in a rat partial bladder outlet obstruction model .…”

Concise Review: Tissue Engineering of Urinary Bladder; We Still Have a Long Way to Go?

“…The wall of the neobladder needs to be prevascularized to avoid graft necrosis since diffusion alone is not sufficient to maintain tissue oxygenation. In order to obtain sufficient functional results, an abundance of vascular networks is required to guarantee blood supply to metabolically active bladder walls rich in muscle . A recognized cause of continual bladder loss of function is the deteriorated microvasculature .…”