The effect of pentoxifylline on detrusor muscle contractility after partial urethral obstruction in a rat model

Comparison between combination of tamsulosin and Pentoxifylline versus tamsulosin alone in the treatment of lower urinary tract symptoms due to benign prostate hyperplasia: A preliminary study

BACKGROUND

In older adults, bladder outlet obstruction (BOO) is prevalent, primarily due to benign prostatic hyperplasia (BPH). These patients' lower urinary tract symptoms can be treated surgically and with medical therapy. Compared to standard treatment with tamsulosin, Pentoxifylline, a phosphodiesterase inhibitor, could benefit patients with BOO due to its properties on microcirculatory blood flow and oxygenation of ischemic tissues. Hence, this trial intended to study the efficacy of Pentoxifylline combined with tamsulosin in treating BOO patients.

MATERIALS AND METHODS

This randomized, double-blind clinical trial recruited 60 patients with BPH from a single center in 2022. Upon consent of patients meeting the eligibility criteria, they were randomly allocated to intervention (Pentoxifylline + tamsulosin) and control (placebo + tamsulosin) groups. The patients were evaluated for international prostate symptom score (IPSS), quality of life (QoL), maximum urinary flow rate (Qmax ) by uroflowmetry, and post-void residual volume (PVR) by abdominal sonography at the onset of the study and after the 12th week.

RESULTS

Patients who used the combination therapy had significantly better results of prostate symptoms and quality of life improvement (IPSS: -36.6%, QoL: -45.3%) compared to patients who received tamsulosin alone (IPSS: -21.2%, QoL: -27.7%) (p < .001). Also, this study shows that the improvement in maximum urinary flow rate and residual volume by combination therapy is significantly higher (Qmax : +42.5%, PVR: -42.6%) compared to monotherapy (Qmax : +25.1%, PVR: -26.1%) (p < .001).

CONCLUSION

When combined with tamsulosin, Pentoxifylline could significantly improve the lower urinary symptoms of BPH patients. It is well tolerated, and the treatment outcomes are better in patients who receive the combination of Pentoxifylline and tamsulosin than those who only receive tamsulosin.

Expression of NGF, MCP-1, uroplakin III, and NOS in bladder urothelium after partial urethral obstruction in rats

INTRODUCTION

Although several cytokines, chemokines, and growth factors have been suggested to play a role in the development of bladder fibrosis and functional changes, the mechanisms that are effective in the pathogenesis of partial bladder outlet obstruction (pBOO)-induced bladder fibrosis are not well understood.

OBJECTIVE

We investigated the expressions of nerve growth factor (NGF), monocyte chemoattractant protein-1 (MCP-1), uroplakin III (URPIII), inducible nitric oxide synthase (iNOS), and endothelial NOS (eNOS) that may be involved in fibrosis in rats with partial urethral obstruction for 1, 2 and 3 weeks, and the changes in the associated ischemic and inflammatory processes. After 1, 2, and 3 weeks of pBOO, blood samples were collected for assessment of renal function from the rats under anesthesia. The bladders were dissected for the tissue antioxidant enzyme activities and lipid peroxidation, including malondialdehyde (MDA), superoxide dismutase (SOD), total antioxidant status (TAS) and total oxidant status (TOS). The immunohistochemical studies were performed. Histopathologically, the number of urothelial layers was calculated and the thickness of the detrusor smooth muscle and lamina propria were quantitatively measured. Additionally, the edema and congestion in the submucosa were evaluated.

STUDY DESIGN

Twenty-eight male Sprague-Dawley rats were used in this study. Three separate experimental groups of pBOO (1 week [n = 7], 2 weeks [n = 7], and 3 weeks [n = 7]) were created, with an additional sham-operated control group (n = 7).

RESULTS

The MDA levels increased in pBOO groups. The SOD values were decreased in the pBOO group for 1 week, and higher in the 3-week pBOO group. The TAS levels were increased in the 3 week pBOO group. The TOS levels increased in the pBOO groups. The number of urothelial layers was decreased in pBOO groups. The lamina propria, the smooth muscle thickness, edema and congestion were increase in the 1 and 2 week pBOO groups. The NGF and MCP-1 expression was increased in the 1-week and 2-week pBOO groups. The expression of URPIII in the epithelium gradually increased in the pBOO groups. In the pBOO groups, iNOS expression in the epithelium cells was significantly elevated. However, the eNOS expression was also significantly increased in the 2 week pBOO group.

CONCLUSION

Our study shows that overexpression of immunohistochemical parameters together with the negative effects of ischemic and inflammatory processes that subjected to pBOO for 1, 2 and 3 weeks may play a potential role in detrusor fibrosis in the rat bladders induced by pBOO. However, understanding of the immunohistochemical parameters investigated in this experimental study is limited, and further studies targeting their relationship to pBOO could help us develop new strategies.

Effects of varying degrees of partial bladder outlet obstruction on urinary bladder function of rats: A novel link to inflammation, oxidative stress and hypoxia

OBJECTIVES

The aim of the present study was to investigate the effects of different degrees of obstruction, and the roles of inflammation, oxidative stress, and hypoxia parameters on bladder function.

METHODS

Thirty male Sprague-Dawley rats were divided into 3 groups (n = 10 in each group): (i) sham-operated control; (ii) severe partial bladder outlet obstruction (PBOO); and (iii) moderate PBOO. Severe and moderate PBOO were induced by urethral ligation using 3-Fr and 4-Fr catheters, respectively, for 6 weeks. After 6 weeks, the in vitro contractile responses to carbachol, electrical field stimulation, ATP and KCl were measured in bladder strips. In addition, mRNA and protein expression of nuclear factor kappa B (NF-κB) hypoxia-inducible factor (HIF) and nuclear factor, erythroid 2-like 2 (Nrf2) in bladder were determined by real-time polymerase chain reaction and western blotting. Malondialdehyde (MDA) levels in bladder tissues were also determined.

RESULTS

Rats in the severe PBOO group had the highest bladder weight. Detrusor strips from rats in the severe PBOO group exhibited 61%-82% smaller contractile responses to all four stimuli than those from the sham-operated group. Activity of NF-κB as an inflammatory marker was increased in the severe PBOO group, whereas HIF-1α and HIF-2β protein levels were increased significantly in the moderate PBOO group. A master regulator of oxidative stress, Nrf2 expression was increased in all obstructed rats. MDA levels were higher in the severe PBOO group than in sham-operated group.

CONCLUSION

The results of the present study reveal the importance of oxidative stress-induced NF-κB signaling in bladder dysfunction with severe obstruction. Altered HIF signaling may contribute to the functional impairment after PBOO. Novel and evolving therapies targeting oxidative and/or inflammatory pathways may be a reasonable strategy for the management of lower urinary tract symptoms or benign prostatic hyperplasia.