This study was designed to evaluate the protective effect of CPD1, a novel phosphodiesterase 5 inhibitor, on renal interstitial fibrosis after unilateral renal ischemia-reperfusion injury (UIRI). Male BALB/c mice were subjected to UIRI, and treated with CPD1 once daily (i.g, 5 mg/kg). Contralateral nephrectomy was performed on day 10 after UIRI, and the UIRI kidneys were harvested on day 11. Hematoxylin-eosin (HE), Masson trichrome and Sirius Red staining methods were used to observe the renal tissue structural lesions and fibrosis. Immunohistochemical staining and Western blot were used to detect the expression of proteins related to fibrosis. HE, Sirius Red and Masson trichrome staining showed that CPD1-treated UIRI mice had lower extent of tubular epithelial cell injury and deposition of extracellular matrix (ECM) in renal interstitium compared with those in the fibrotic mouse kidneys. The results from immunohistochemistry and Western blot assay indicated significantly decreased protein expressions of type I collagen, fibronectin, plasminogen activator inhibitor-1 (PAI-1) and α-smooth muscle actin (α-SMA) after CPD1 treatment. In addition, CPD1 dose-dependently inhibited the expression of ECM-related proteins induced by transforming growth factor β1 (TGF-β1) in normal rat kidney interstitial fibroblasts (NRK-49F) and human renal tubular epithelial cell line (HK-2). In summary, the novel PDE inhibitor, CPD1, displays strong protective effects against UIRI and fibrosis by suppressing TGF-β signaling pathway and regulating the balance between ECM synthesis and degradation through PAI-1.
Animals ; Humans ; Male ; Mice ; Rats ; Extracellular Matrix Proteins ; Fibrosis ; Kidney ; Kidney Diseases ; Phosphodiesterase 5 Inhibitors ; Plasminogen Activator Inhibitor 1

Cavernous nerve injury is an important cause of erectile dysfunction (ED). Although protective nerve technology has been widely used in nerve-sparing radical prostatectomy (nsRP), the incidence of ED is still very high after surgery. The purpose of our study was to evaluate erectile function (EF) and penile length in the non-erectile state (PLNES) following scheduled phosphodiesterase 5 inhibitor (PDE5i), vacuum erectile device (VED) treatment, and combination therapy after nsRP. One hundred patients with localized prostate cancer and normal EF were randomized to scheduled PDE5i group, VED treatment group, a combined treatment group, and the control group without any intervention. The International Index of Erectile Function-5 (IIEF-5) scores and PLNES were evaluated after 6 months and 12 months of treatment. Sexual Encounter Profile (SEP-Question 2 and SEP-Question 3) were evaluated after 12 months of treatment. Ninety-one of the 100 randomized patients completed the study. We found that the 5 mg tadalafil once a day (OaD) combined with VED can help improve IIEF-5 scores in nsRP patients after both 6 months and 12 months. VED alone or combined with tadalafil OaD can help patients maintain PLNES. VED combined with tadalafil OaD can improve the rate of successful penetration (SEP-Question 2) after 12 months. There were no significant differences in the return to target EF after 12 months among the groups. No significant correlation was noted between the variables and return to target EF (IIEF ≥ 17), and between the variables and effective shortening of the patient's penis (shortening ≥ 1 cm) after 12 months of intervention.
Erectile Dysfunction ; Humans ; Male ; Penile Erection ; Phosphodiesterase 5 Inhibitors ; Prospective Studies ; Prostatectomy ; Prostatic Neoplasms ; Tadalafil ; Treatment Outcome ; Vacuum

Noninvasive low-intensity extracorporeal shockwave treatment (Li-ESWT) has been widely used to treat erection disorders. There is no clear information regarding either the selection of patients for the treatment or the treatment protocol. In this study, we aimed to investigate the efficacy of extracorporeal shockwave therapy in diabetic patients with severe erectile dysfunction (International Index of Erectile Function-5 [IIEF-5] scores of 5 to 7). Sixty-three diabetes mellitus patients with erectile dysfunction having IIEF-5 scores of 5 to 7 and not showing a recovery of potency despite phosphodiesterase type 5 inhibitor therapy for the past 6 months were included in the study. The patients were evaluated based on their IIEF-5 scores and Erection Hardness Scale scores. The IIEF-5 score (mean ± standard deviation [s.d.]) increased from 5.29 ± 1.67 to 5.56 ± 1.85, with a difference of 0.27 ± 0.18 (P > 0.05). The Erection Hardness Scale scores (mean ± s.d.), on the other hand, increased from 1.46 ± 0.50 to 1.48 ± 0.50, with a difference of 0.02 ± 0 (P > 0.05). In conclusion, the response to phosphodiesterase type 5 inhibitors did not change after extracorporeal shockwave treatment in diabetes mellitus patients with severe erectile dysfunction (IIEF-5 scores of 5 to 7).
Diabetes Mellitus ; Erectile Dysfunction ; Extracorporeal Shockwave Therapy ; Humans ; Male ; Penile Erection ; Phosphodiesterase 5 Inhibitors ; Treatment Outcome

Silent information regulator 2-related enzyme 1 (SIRT1) is an aging-related protein activated with aging. Herein, we evaluated the role of SIRT1 in aging-related erectile dysfunction. The expression of SIRT1 was modulated in aged Sprague-Dawley rats following intragastric administration of resveratrol (Res; 5 mg kg^-1), niacinamide (NAM; 500 mg kg^-1) or Res (5 mg kg^-1) + tadalafil (Tad; phosphodiesterase-5 [PDE5] inhibitor; 5 mg kg^-1) for 8 weeks. Then, we determined erectile function by the ratio of intracavernosal pressure (ICP)/mean systemic arterial pressure (MAP). Cavernosal tissues were extracted to evaluate histological changes, cell apoptosis, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP), the superoxide dismutase (SOD)/3,4-methylenedioxyamphetamine (MDA) level, and the expression of SIRT1, p53, and forkhead box O3 (FOXO3a) using immunohistochemistry, terminal deoxynucleotidyl transferase (TdT)-mediated 2'-deoxyuridine 5'-triphosphate (dUTP) nick-end labeling (TUNEL), enzyme-linked immunosorbent assays, and western blot analysis. Compared with the control, Res treatment significantly improved erectile function, reflected by an increased content of smooth muscle and endothelium, NO/cGMP and SOD activity, and reduced cell apoptosis and MDA levels. The effect of Res was improved by adding Tad. In addition, the protein expression of SIRT1 was increased in the Res group, accompanied by decreased p53 and FOXO3a levels. In addition, inhibition of SIRT1 by NAM treatment resulted in adverse results compared with Res treatment. SIRT1 activation ameliorated aging-related erectile dysfunction, supporting the potential of SIRT1 as a target for erectile dysfunction treatment.
Animals ; Male ; Rats ; Cyclic GMP/metabolism* ; Erectile Dysfunction/metabolism* ; Nitric Oxide/metabolism* ; Penile Erection ; Penis/pathology* ; Phosphodiesterase 5 Inhibitors/pharmacology* ; Rats, Sprague-Dawley ; Sirtuin 1/metabolism* ; Superoxide Dismutase/metabolism* ; Tumor Suppressor Protein p53/metabolism*

PURPOSE: To examine the association between phosphodiesterase type 5 (PDE5) inhibitor use and melanoma by 1) conducting a systematic review of observational studies; and 2) determining if low PDE5A gene expression in human melanoma correlated with decreased overall survival. MATERIALS AND METHODS: A systematic search of observational studies examining the association between PDE5 inhibitor use and melanoma was performed through ClinicalTrials.gov, the Cochrane Library, EMBASE, PubMed, and Web of Science databases, and seven eligible studies were identified. PDE5A gene expression was analyzed with RNA sequencing data from 471 human melanoma samples obtained from The Cancer Genome Atlas. RESULTS: Four studies reported a positive association between PDE5 inhibitor use and melanoma, and three studies found no correlation. RNA sequencing data analysis revealed that under-expression of the PDE5A gene did not impact clinical outcomes in melanoma. CONCLUSIONS: There is currently no evidence to suggest that PDE5 inhibition in patients causes increased risk for melanoma. The few observational studies that demonstrated a positive association between PDE5 inhibitor use and melanoma often failed to account for major confounders. Nonetheless, the substantial evidence implicating PDE5 inhibition in the cyclic guanosine monophosphate (cGMP)-mediated melanoma pathway warrants further investigation in the clinical setting.
Gene Expression ; Genome ; Guanosine Monophosphate ; Humans ; Melanoma ; Phosphodiesterase 5 Inhibitors ; Sequence Analysis, RNA ; Sildenafil Citrate ; Statistics as Topic ; Tadalafil ; Vardenafil Dihydrochloride

Obesity is a major public health issue worldwide and is frequently associated with erectile dysfunction (ED). Both conditions may share an internal pathologic environment, also known as common soil. Their main pathophysiologic processes are oxidative stress, inflammation, and resultant insulin and leptin resistance. Moreover, the severity of ED is correlated with comorbid medical conditions, including obesity. Therefore, amelioration of these comorbidities may increase the efficacy of ED treatment with phosphodiesterase 5 inhibitors, the first-line medication for patients with ED. Although metformin was originally developed as an insulin sensitizer six decades ago, it has also been shown to improve leptin resistance. In addition, metformin has been reported to reduce oxidative stress, inflammatory response, and body weight, as well as improve ED, in animal and human studies. Moreover, administration of a combination of metformin and phosphodiesterase 5 inhibitors improves erectile function in patients with ED who have a poor response to sildenafil and are insulin resistant. Thus, concomitant treatment of metabolic derangements associated with obesity in patients with ED who are obese would improve the efficacy and reduce the refractory response to penile vasodilators. In this review, we discuss the connecting factors between obesity and ED and the possible combined treatment modalities.
Animals ; Body Weight ; Comorbidity ; Erectile Dysfunction ; Humans ; Inflammation ; Insulin ; Leptin ; Male ; Metformin ; Obesity ; Oxidative Stress ; Phosphodiesterase 5 Inhibitors ; Public Health ; Sildenafil Citrate ; Soil ; Vasodilator Agents

BACKGROUND AND OBJECTIVES: Udenafil, a new phosphodiesterase-5 inhibitor (PDE5i), has been used to treat erectile dysfunction. Given the proven benefit of PDE5i in pulmonary arterial hypertension (PAH), we evaluated serial hemodynamic changes after single udenafil administration to determine the appropriate therapeutic dose. METHODS: Eighteen patients were randomly allocated into one of 3 groups: placebo, udenafil 50 mg (U50), and udenafil 100 mg (U100). Diagnosis for inclusion was idiopathic PAH or PAH associated with connective tissue disease. Patients with any contraindication to PDE5i, and/or PDE5i treatment in the past 1 month were excluded. Continuous hemodynamic monitoring was performed by placing a Swan-Ganz catheter. Information on cardiac index (CI), mean pulmonary arterial pressure (mPAP), mean systemic arterial pressure (mSAP), pulmonary arterial wedge pressure (PAWP), and pulmonary vascular resistance index (PVRI) was obtained for 4 hours after drug administration. RESULTS: The mPAP significantly decreased in both the U50 and U100 (−11 mmHg and −8 mmHg from baseline, respectively, p < 0.1). The mSAP also decreased in both U50 and U100; however, the decrease was greater in the U100 (Δ=−8.5 mmHg and Δ=−14.0 mmHg). CI increased in the U50, but decreased in the U100. Although PVRI decreased in both, statistical significance was only achieved in the U50 compared to placebo. PAWP was stable during monitoring. U50 had at least 4 hour-effect after administration. Only 2 patients with U100 experienced mild adverse events. CONCLUSIONS: This is the first demonstration of the acute hemodynamic changes induced by udenafil. U50 is considered an optimal dose for treating PAH with more than 4-hour treatment effect. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01553721.
Arterial Pressure ; Catheters ; Connective Tissue Diseases ; Cyclic Nucleotide Phosphodiesterases, Type 5 ; Diagnosis ; Erectile Dysfunction ; Hemodynamics ; Humans ; Hypertension ; Hypertension, Pulmonary ; Male ; Phosphodiesterase 5 Inhibitors ; Pulmonary Wedge Pressure ; Vascular Resistance

We aimed to determine whether combination of LIM-kinase 2 inhibitor (LIMK2i) and phosphodiesterase type-5 inhibitor (PDE5i) could restore erectile function through suppressing cavernous fibrosis and improving cavernous apoptosis in a rat model of cavernous nerve crush injury (CNCI). Seventy 12-week-old Sprague-Dawley rats were equally distributed into five groups as follows: (1) sham surgery (Group S), (2) CNCI (Group I), (3) CNCI treated with daily intraperitoneal administration of 10.0 mg kg^-1 LIMK2i (Group I + L), (4) daily oral administration of 20.0 mg kg^-1 udenafil, PDE5i (Group I + U), and (5) combined administration of 10.0 mg kg^-1 LIMK2i and 20.0 mg kg^-1 udenafil (Group I + L + U). Rats in Groups I + L, I + U, and I + L + U were treated with respective regimens for 2 weeks after CNCI. At 2 weeks after surgery, erectile response was assessed using electrostimulation. Penile tissues were processed for histological studies and western blot. Group I showed lower intracavernous pressure (ICP)/mean arterial pressure (MAP), lower area under the curve (AUC)/MAP, decreased immunohistochemical staining for alpha-smooth muscle (SM) actin, higher apoptotic index, lower SM/collagen ratio, increased phospho-LIMK2-positive fibroblasts, decreased protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) phosphorylation, increased LIMK2/cofilin phosphorylation, and increased protein expression of fibronectin, compared to Group S. In all three treatment groups, erectile responses, protein expression of fibronectin, and SM/collagen ratio were improved. Group I + L + U showed greater improvement in erectile response than Group I + L. SM content and apoptotic index in Groups I + U and I + L + U were improved compared to those in Group I. However, Group I + L did not show a significant improvement in SM content or apoptotic index. The number of phospho-LIMK2-positive fibroblasts was normalized in Groups I + L and I + L + U, but not in Group I + U. Akt/eNOS phosphorylation was improved in Groups I + U and I + L + U, but not in Group I + L. LIMK2/cofilin phosphorylation was improved in Groups I + L and I + L + U, but not in Group I + U. Our data indicate that combined treatment of LIMK2i and PDE5i immediate after CN injury could improve erectile function by improving cavernous apoptosis or eNOS phosphorylation and suppressing cavernous fibrosis. Rectification of Akt/eNOS and LIMK2/cofilin pathways appears to be involved in their improvement.
Animals ; Apoptosis/drug effects* ; Arterial Pressure ; Electric Stimulation ; Erectile Dysfunction/pathology* ; Lim Kinases/antagonists & inhibitors* ; Male ; Nerve Crush ; Nitric Oxide Synthase Type III/metabolism* ; Penis/pathology* ; Peripheral Nerve Injuries/pathology* ; Phosphodiesterase 5 Inhibitors/therapeutic use* ; Phosphorylation ; Pyrimidines/therapeutic use* ; Rats ; Rats, Sprague-Dawley ; Sulfonamides/therapeutic use*

This study aimed to evaluate whether adding a vacuum erection device (VED) to regular use of Tadalafil could achieve better penile rehabilitation following posterior urethroplasty for pelvic fracture-related urethral injury (PFUI). Altogether, 78 PFUI patients with erectile dysfunction (ED) after primary posterior urethroplasty were enrolled and divided into two treatment groups: VED combined with Tadalafil (Group 1, n = 36) and Tadalafil only (Group 2, n = 42). Changes in penile length, testosterone level, International Index of Erectile Function-5 (IIEF-5) questionnaire, Quality of Erection Questionnaire (QEQ), and nocturnal penile tumescence (NPT) testing were used to assess erectile function before and after 6 months of ED treatment. Results showed that the addition of VED to regular use of Tadalafil preserved more penile length statistically (0.4 ± 0.9 vs -0.8 ± 0.7 cm, P < 0.01). IIEF-5 score and QEQ score in Group 1 were higher than Group 2 (both P < 0.05). After treatment, 21/36 (58.3%) Group 1 patients and 19/42 (45.2%) Group 2 patients could complete vaginal penetration. Group 1 patients also had markedly improved testosterone levels (P = 0.01). Unexpectedly, there was no significant difference in NPT testing between two therapies. For PFUI patients with ED after posterior urethroplasty, the addition of VED to regular use of Tadalafil could significantly improve their conditions - improving erection and increasing penile length - thus increasing patient satisfaction and confidence in penile rehabilitation.
Adult ; Combined Modality Therapy/methods* ; Erectile Dysfunction/rehabilitation* ; Humans ; Male ; Middle Aged ; Penile Erection ; Penis/surgery* ; Phosphodiesterase 5 Inhibitors/therapeutic use* ; Tadalafil/therapeutic use* ; Treatment Outcome ; Urethra/surgery* ; Vacuum ; Young Adult

Benign prostatic hyperplasia (BPH) with lower urinary tract symptoms (LUTS) is a common disease with frequent occurrence in elderly men, and its incidence shows a significant positive correlation with age. Evidence has confirmed that BPH/LUTS is closely related to erectile dysfunction (ED) and significantly affects the quality of life of elderly males. Phosphodiesterase 5 inhibitors (PDE5i) can improve both ED and BPH/LUTS of the patients and PDE5 is expected to be a new therapeutic target for BPH/LUTS with ED. This review explores the structure and function of PDE5 and the action mechanisms of PDE5i so as to provide a more effective strategy for the clinical treatment of BPH/LUTS with ED.
Aged ; Drug Therapy, Combination ; Erectile Dysfunction ; complications ; drug therapy ; Humans ; Lower Urinary Tract Symptoms ; complications ; drug therapy ; Male ; Phosphodiesterase 5 Inhibitors ; therapeutic use ; Prostatic Hyperplasia ; complications ; drug therapy ; Quality of Life