Effects of phosphodiesterase 5 inhibitors on sperm parameters and fertilizing capacity

The aim of this review study is to elucidate the effects that phosphodiesterase 5 （PDE5） inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase （AC） system and the cGMP/guanylate cyclase （GC） system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide （NO） leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil＇s actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the improvement of the outcome of assisted reproductive technology （ART） programs. In the future PDE5 inhibitors might serve as adjunct therapeutical agents for the alleviation of male infertility.

Erectile potentials of a new phosphodiesterase type 5 inhibitor, DA-8159, in diet-induced obese rats

Aim： To examine the changes in the erectile function in diet-induced obese rats and investigate the oral efficacy of DA-8159, a new phosphodiesterase type 5 （PDE5） inhibitor, on penile erection in obese rats. Methods： The rats were fed a high-energy diet for 12 weeks and divided into three groups： an obesity-resistant （OR） control group, an obesity-prone （OP） control group, and an OP-DA-8159 treatment （DA-8159） group. The electrostimulation-induced erectile responses were measured in all groups. The body weight, plasma cholesterol, triglyceride and glucose levels were also measured. Results： In the OP control group, the maximum intracavernous pressure （ICP） and ICP/blood pressure （ICP/BP） ratio after electric stimulation were significantly lower than those in OR control group. The corresponding area under the curve （AUC） of the ICP/BP ratio, the detumescence time and the baseline cavernous pressure were also lower than those in the OR control group, but this difference was not significant. The body weight gain, plasma cholesterol and triglyceride level in the OP group were significantly higher than those in the OR group. After administering the DA-8159, a significant increase in the maximum ICP and the ICP/BP ratio were observed. The corresponding AUCs in the DA-8159 group were also higher than those in the two control groups. Furthermore, the detumescence time was significantly prolonged after treatment with DA-8159. Conclusion： These results demon- strate that diet-induced obesity affects the erectile function in rats and these erectile dysfunction （ED） can be improved by the treatment with DA-8159, indicating DA-8159 might be a treatment option for ED associated with obesity.

Incidence rate of prostate cancer in men treated for erectile dysfunction with phosphodiesterase type 5 inhibitors： retrospective analysis

The purpose of this study was to determine the incidence rate of prostate cancer among men with erectile dysfunction （ED） treated with phosphodiesterase type 5 inhibitors （PDE-5i） over a 7-year period vs. men with ED of the same age and with similar risk factors who were not treated with PDE-5i. In a retrospective review of electronic medical records and billing databases between the years 2000 and 2006, men with ED between the ages of 50 and 69 years and no history of prostate cancer prior to 2000 were identified. These individuals were divided into two groups： 2362 men who had treatment with PDE-5i, and 2612 men who did not have treatment. Demographic data in each group were compared. During the study period, 97 （4.1%） men with ED treated with PDE-5i were diagnosed with prostate cancer compared with 258 （9.9%） men with ED in the non-treated group （P〈00001）. A higher percentage of African Americans were treated with PDE-5i vs. those who were not （10.5% vs. 7.1%; P〈O.O001）. The PDE-5i group had lower documented diagnosis of elevated prostate-specific antigen （10.0% vs. 13.1%; P=-0.0008） and higher percentage of benign prostatic hyperplasia （38.4% vs. 35.1%; P=0.0149）. Men with ED treated with PDE-5i tended to have less chance （adjusted odds ratio： 0.4; 95% confidence intervals： 0.3-0.5; P〈0.0001） of having prostate cancer. Our data suggest that men with ED treated with PDE-5i tended to have less of a chance of beine diaenosed with orostate cancer. Further research is warranted.

Evaluation and diagnostic testing of erectile dysfunction in the era of phosphodiesterase type 5 inhibitors

The diagnosis and treatment of erectile dysfunction has changed dramatically since the availability of safe and effective oral therapies. Unfortunately, not all men can be adequately treated in this way, and might require more invasive testing to diagnose and treat the specific cause of their dysfunction. This review looks at the tests and strategies available for men who cannot be treated by oral therapy alone.

Erectile dysfunction: on the efficacy of a phosphodiesterase inhibitor in patients with multiple risk factors

1 Introduction With the 1998 introduction of sildenafil (Viagra), the first available oral phosphodiesterase inhibitor, there

The use of antimuscarinics,phosphodiesterase type Ⅴ inhibitors and phytotherapy for lower urinary tract symptoms in men

Besides the mainstay of α-blockers and 5α-reductase inhibitors,other forms of medical therapy complete the armamentarium in the treatment of lower urinary tract symptoms(LUTS)in men.These treatments can target specific symptoms as well as associated symptoms that would affect the quality of life of the patients.Many patients are bothered by storage symptoms,more so than the voiding symptoms.Antimuscarinics are efficacious and safe,provided the patients do not have high post void residual urine.Many patients with LUTS also have erectile dysfunction,and phosphodiesterase type Ⅴ inhibitors are effective in relieving both LUTS as well as erectile dysfunction for such patients.Phytotherapy provides a popular and safe treatment for LUTS,however,the efficacy of the treatment has not been proven in well conducted prospective randomized controlled studies.

Effect of phosphodiesterase inhibitors in the bladder

Many aging men will experience lower urinary tract symptoms(LUTS).Phosphodiesterase type 5(PDE5)inhibitors have shown promise in treating LUTS in these patients.PDE5 inhibitors mediate their effects through several pathways including cAMP,NO/cGMP,Kchannel modulated pathways,and the L-cysteine/H2S pathway.PDE5 inhibitors exert their effect in muscle cells,nerve fibers,and interstitial cells(ICs).The use of PDE5 inhibitors led to improvement in LUTS.This included urodynamic parameters.PDE5 inhibitors may play a significant role in LUTS due to their effect on the bladder rather than the prostate.

Are phosphodiesterase type 5 inhibitors effective for the management of lower urinary symptoms suggestive of benign prostatic hyperplasia?

AIM: To review the efficacy of phosphodiesterase type 5 inhibitors(PDE5-Is) in lower urinary tract symptoms(LUTS) suggestive of benign prostate hyperplasia(LUTS/BPH). METHODS: A comprehensive research was conducted to identify all publications relating to benign prostate hyperplasia and treatment with sildenafil, vardenafil and tadalafil. To assess the efficacy, the changes in total international prostate symptom score(IPSS), IPSS subscore including voiding, storage and quality of life(Qo L), Benign prostatic hyperplasia Impact Index(BII), maximum urinary flow rate(Qmax) and the International Index of Erectile Function(IIEF) were extracted. A meta-analytical technique was used for the analysis of integrated data from the included studies to evaluate the mean difference in the results. RESULTS: Total IPSS score, IIEF and BII showed a significant improvement in trials in which LUTS/BPH with or without erectile dysfunction(ED) were compared with the placebo. For LUTS/BPH, the mean differences of total IPSS score, IIEF and BII are-2.17, 4.88 and-0.43, P < 0.00001, respectively. For LUTS/BPH with comorbid ED, the mean difference are-1.97, 4.54 and-0.52, P < 0.00001, respectively. PDE5-Is appear to improve IPSS storage, voiding and Qo L subscore(mean difference =-0.71,-1.23 and-0.33, P < 0.00001, respectively). Although four doses of tadalafil(2.5, 5, 10 and 20 mg) failed to reach significance in Qmax(mean difference = 0.22, P = 0.10), the 5 mg dose of tadalafil significantly improved the Qmax(mean difference = 0.33, P = 0.03).CONCLUSION: PED5-Is demonstrated efficacy for improving LUTS in BPH patients with or without ED and could be considered to be the first line treatment for LUTS/BPH.

Erectile dysfunction: on the efficacy of a phosphodiesterase inhibitor with concurrent sex therapy

1 Introduction Erectile dysfunction (ED) is a condition that affects perhaps 25 to 30 million men in the U.S.A. constituting

Combined phosphodiesterase inhibitors in end-stage heart failure: A case presentation

Heart failure (HF) is the leading cause of morbidity and mortality and is evolving to epidemic proportions. Despite pharmacologic advances and device interventions, HF remains a progressive disease. The phosphodiesterase inhibitors-3 (PDE3I), and more recently, the phosphodiesterase inhibitors-5 (PDE5I) have been used as part of the treatment in certain patients, however, such combination has not been studied or reported before.

Statin, testosterone and phosphodiesterase 5-inhibitor treatments and age related mortality in diabetes

AIMTo determine how statins, testosterone (T) replacement therapy (TRT) and phosphodiesterase 5-inhibitors (PDE5I) influence age related mortality in diabetic men.METHODSWe studied 857 diabetic men screened for the BLAST study, stratifying them (mean follow-up = 3.8 years) into: (1) Normal T levels/untreated (total T > 12 nmol/L and free T > 0.25 nmol/L), Low T/untreated and Low T/treated; (2) PDE5I/untreated and PDE5I/treated; and (3) statin/untreated and statin/treated groups. The relationship between age and mortality, alone and with T/TRT, statin and PDE5I treatment was studied using logistic regression. Mortality probability and 95%CI were calculated from the above models for each individual.RESULTSAge was associated with mortality (logistic regression, OR = 1.10, 95%CI: 1.08-1.13, P < 0.001). With all factors included, age (OR = 1.08, 95%CI: 1.06-1.11, P < 0.001), Low T/treated (OR = 0.38, 95%CI: 0.15-0.92, P = 0.033), PDE5I/treated (OR = 0.17, 95%CI: 0.053-0.56, P = 0.004) and statin/treated (OR = 0.59, 95%CI: 0.36-0.97, P = 0.038) were associated with lower mortality. Age related mortality was as described by Gompertz, r2 = 0.881 when Ln (mortality) was plotted against age. The probability of mortality and 95%CI (from logistic regression) of individuals, treated/untreated with the drugs, alone and in combination was plotted against age. Overlap of 95%CI lines was evident with statins and TRT. No overlap was evident with PDE5I alone and with statins and TRT, this suggesting a change in the relationship between age and mortality.CONCLUSIONWe show that statins, PDE5I and TRT reduce mortality in diabetes. PDE5I, alone and with the other treatments significantly alter age related mortality in diabetic men.

Phosphodiesterase inhibitors for treatment of voiding dysfunction: An overview of experimental and clinical evidence

Recently,the focus of the origin of lower urinary tract symptoms(LUTS)has change from the prostate to the bladder.Regardless of the underlying mechanism associated with the origin of LUTS,alpha-blockers continue to be the most common medicine prescribed to treat LUTS due to benign prostatic obstruction(BPO).The newest class of drug introduced to treat LUTS/BPO is phosphodiesterase inhibitors(PDEi)and the aim of this study was to review the role of PDEi in the treatment of LUTS/BPO.In this review,the first evidence was evaluated based on epidemiological studies followed by randomized clinical trials which provide evidence on the administration of PDEi in patients with LUTS/BPO.Experimental studies were also assessed to tentatively elucidate the association between LUTS and erectile dysfunction,and to elucidate the underlying mechanism.There is still controversy regarding the administration of PDEi due to the fear of detrusorimpairment,response to acute administration,and the effects of PDEi combined with alpha-blockers.Following this review,we conclude that treatment of BPO/LUTS with PDEi is beneficial,based on experimental studies,strong evidence and the large number of randomized clinical trials confirming their efficiency.

EFFECTS OF NOVEL PHOSPHODIESTERASE 4 INHIBITORS,ARIFLO AND SB242126A, ON ENDOTHELIN-1-INDUCED CONTRACTILITY OF ISOLATED HUMAN MYOMETRIUM

Objective To investigate the effects of novel selective phosphodiesterase4 (PDE4) inhibitors,Ariflo and SB242126A, on the endothelin-1 (ET-1) - induced contractility occurring in nonpregnant human myome-trium specimens. Methods Contractile responses to Ariflo and SB242126A were recorded cumulatively on isola-ted human longitudinal myometrium specimens obtained through surgical operations. Results Ariflo andSB242126A could inhibit both the frequency and amplitude of spontaneous contractions of myometrium (pD2 =8. 6and 7. 6,n =4) and ET-1 -induced contractions in a concentration-dependent manner (pD2 = 7. 7 and 8. 1 ,n =5) ,with a potency similar to that of Rolipram. Conclusion Ariflo and SB242126A have an obvious inhibitory effecton endothelin-1-induced contractility of isolated human myometrium. The finding suggested that PDE4 inhibitorsmight have clinical potential in treating preterm labour and dysmenorrhoea.

Erectile potentials of a new phosphodiesterase type 5 inhibitor,DA-8159,in diet-induced obese rats

Aim:To examine the changes in the erectile function in diet-induced obese rats and investigate the oral efficacy of DA-8159,a new phosphodiesterase type 5(PDE5)inhibitor,on penile erection in obese rats.Methods:The rats were fed a high-energy diet for 12 weeks and divided into three groups:an obesity-resistant(OR)control group,an obesity- prone(OP)control group,and an OP-DA-8159 treatment(DA-8159)group.The electrostimulation-induced erectile responses were measured in all groups.The body weight,plasma cholesterol,triglyceride and glucose levels were also measured.Results:In the OP control group,the maximum intracavernous pressure(ICP)and ICP/blood pressure(ICP/BP)ratio after electric stimulation were significantly lower than those in OR control group.The corresponding area under the curve(AUC)of the ICP/BP ratio,the detumescence time and the baseline cavernous pressure were also lower than those in the OR control group,but this difference was not significant.The body weight gain,plasma cholesterol and triglyceride level in the OP group were significantly higher than those in the OR group. After administering the DA-8159,a significant increase in the maximum ICP and the ICP/BP ratio were observed.The coerrsponding AUCs in the DA-8159 group were also higher than those in the two control groups.Furthermore,the detumescence time was significantly prolonged after treatment with DA-8159.Conclusion:These results demon- strate that diet-induced obesity affects the erectile function in rats and these erectile dysfunction(ED)can be im- proved by the treatment with DA-8159,indicating DA-8159 might be a treatment option for ED associated with obesity.

Value of phosphodiesterase 5 inhibitors as a combination therapy for treating erectile dysfunction:A literature review

Erectile dysfunction(ED)is increasing in prevalence,with estimates that 50%of men between 40 and 70 years of age suffer from the disease.Due to a wide array of available medical interventions,significant focus has been put on combination therapies that can treat ED refractory to first-line treatments such as phosphodiesterase 5 inhibitors(PDE5is).However,reviews evaluating monotherapy noninferiority and patient satisfaction of monotherapy versus combination therapy are lacking.A thorough PubMed search was performed to evaluate combination therapy in ED treatment.Articles published between January 2008 and June 2023 were reviewed,including randomized control trials,retrospective analyses,and cohort studies.Combination therapies included PDE5i plus another PDE5i,testosterone supplementation,α-blockers,vacuum erectile devices,intracavernosal injections,and low-intensity shockwave therapy.Based on this review,PDE5i monotherapy is not inferior to combination therapy and has increased satisfaction,convenience,and ease of use for patients with ED.Limitations of current literature on combination therapy include small sample size,limited data on patient satisfaction,possible biases,and limited follow-up time.Further studies will need larger randomized control trials with follow-up times greater than 1 year.

Patterns of treatment with PDE5 inhibitors in the clinical practice in Italy： longitudinal data from the Erectile Dysfunction Observational Study

The Erectile Dysfunction Observational Study （EDOS） is a 6-months observational prospective multicentric study enrolling men with erectile dysfunction （ED） who asked, to be started on a treatment or to change a previous treatment. Aims of the study were to analyse the pattern of treatment and compare the efficacy of treatments used. Patients were enrolled during a normal hospital visit and were prescribed a treatment for ED. They were asked at baseline and after 3 and 6 months, to answer a set of questions from the International Index of Erectile Function, Erectile Dysfunction Inventory of Treatment Satisfaction （EDITS） and Short Form of the Psychological and Interpersonal Relationships Scale questionnaires （SF-PAIRS）. Clinicians were free to prescribe any therapy for ED available in the market, and to change therapy at any time during the study. Out of 1 338 patients, available for analysis at 6 months, 624 （47%） changed their treatment during the study and 714 （53%） continued with the drug prescribed at baseline. Patients assuming tadalafil had a significantly higher probability of maintaining the same treatment compared to sildenafil or vardenafil. There was no clinically significant difference in terms of efficacy, patient satisfaction, self-confidence and spontaneity between the different inhibitors of PDE5. The ‘time concerns＇ domain score of SF-PAIRS, was statistically better in patients assuming tadalafil. In conclusion sildenafil, vardenafil and tadalafil show similar efficacy in the clinical practice. However, patients receiving tadalafil display a lower risk to discontinue or change the treatment.

西地那非通过促进巨噬细胞M2型极化缓解慢性盆腔疼痛大鼠痛觉和炎症

目的:探讨磷酸二酯酶5(PDE5)抑制剂西地那非对巨噬细胞极化介导的慢性盆腔疼痛痛觉和炎症的机制。方法:32只成年Wistar大鼠随机分为4组:Sham组、实验性自身免疫性前列腺炎(EAP)组、Sildenafil^(+)EAP组、MET^(+)Sildenafil^(+)EAP组,每组8只。皮下注射前列腺抗原(PAg)和弗氏完全佐剂诱导EAP模型,Sham组注射等量生理盐水,西地那非治疗EAP大鼠,另外,Sildenafil^(+)EAP处理基础上注射巨噬细胞M2型极化抑制剂二甲双胍。HE染色分析前列腺组织病理变化;von Frey纤维法检测大鼠盆腔痛觉反应率;ELISA检测血清细胞因子IL-10和TNF-α水平。流式细胞术检测血清iNOS^(+)和CD16/32^(+)巨噬细胞数量及CD206^(+)、CD10^(+)巨噬细胞数量。结果:与Sham组相比,EAP组前列腺腹侧腺体组织出现明显局灶性或多灶性炎症,盆腔痛觉反应率、血清炎症因子TNF-α水平、巨噬细胞M1型极化特征iNOS^(+)和CD16/32^(+)细胞数量显著升高(均P<0.05),而巨噬细胞M2型极化特征IL-10水平和CD206^(+)、CD10^(+)巨噬细胞数量显著减少(均P<0.05)。与EAP组相比,Sildenafil^(+)EAP组盆腔痛觉反应率、TNF-α水平、iNOS^(+)和CD16/32^(+)细胞数量显著降低(均P<0.05),而IL-10水平和CD206^(+)、CD10^(+)巨噬细胞数量显著升高(均P<0.05)。与Sildenafil^(+)EAP组相比,MET^(+)Sildenafil^(+)EAP组盆腔痛觉反应率、TNF-α水平、iNOS^(+)和CD16/32^(+)细胞数量显著升高(均P<0.05),而IL-10水平和CD206^(+)与CD10^(+)巨噬细胞数量显著降低(均P<0.05)。结论:PDE5抑制剂西地那非通过促进M2巨噬细胞极化阻断慢性盆腔疼痛和炎症。

磷酸二酯酶5在心力衰竭中作用的研究进展

磷酸二酯酶5(PDE5)是环磷酸鸟苷(cGMP)特异性水解酶,是由一氧化氮(NO)激活的可溶性鸟苷酸环化酶(sGC)靶向cGMP产生的。PDE5催化cGMP中磷酸二酯键的水解,从而将cGMP转化为无活性的5′-GMP形式,cGMP-PKG轴功能障碍将引起心脏重塑,是心力衰竭(HF)的主要原因之一。但PDE5抑制剂治疗心力衰竭的临床疗效存在争议。本文总结了近年来PDE5在心力衰竭中的作用机制和研究进展,对未来临床应用PDE5靶向治疗心力衰竭具有重要的指导意义。

磷酸二酯酶4抑制剂在中枢神经系统疾病中的作用研究进展

磷酸二酯酶(PDE)通过催化细胞内的环磷酸腺苷(cAMP)和环磷酸鸟苷(cGMP)的水解参与调节神经元可塑性、突触发生、突触传递、记忆形成和认知功能等细胞生理过程及功能发挥。大量基础和临床研究证明PDE4抑制剂主要通过抑制cAMP水解、提高cAMP含量,增强其下游效应,从而改善中枢神经系统疾病的发生和发展。PDE4抑制剂可提高长时程增强效应、海马神经元cAMP反应元件结合蛋白(CREB)的磷酸化和记忆相关Arc基因的表达,从而改善认知和记忆障碍以及阿尔茨海默病样症状;通过减轻α-突触核蛋白诱导的细胞毒性,增加miR-124-3p对细胞活性的作用而抵抗帕金森病的发生发展;可激活cAMP/PKA/CREB通路,从而减弱神经炎症和氧化应激,增强神经可塑性,改善精神分裂症;通过抑制海马的晚期糖基化终末产物受体(RAGE)、Toll样受体4和NOD样受体热蛋白结构域相关蛋白3通路降低小胶质细胞激活和IL-1β产生,下调HMGB1/RAGE信号通路和抑制炎症因子,在抑郁症中发挥作用;通过减少小脑神经胶质细胞损伤,增加伤害性感受阈值,改善相互学习和记忆缺陷,从而在孤独症谱系障碍的治疗中发挥作用;通过调节cAMP含量影响脆性X智力低下蛋白表达,有望应用于脆性X染色体综合征治疗;促进少突胶质祖细胞分化并增强髓鞘形成而影响多发性硬化症治疗。PDE4与双向情感障碍也有关,可能作为治疗靶点之一。目前还有不少PDE4抑制剂处于中枢神经系统疾病的临床试验阶段。本文综述了PDE4抑制剂治疗中枢神经系统疾病的基础研究和临床试验进展,以期为中枢神经系统疾病的预防和治疗提供新的思路,为中枢神经系统药物的研发提供新策略。

PDE4B专一性抑制剂选择性的起源

采用分子动力学模拟和结合自由能计算研究了PDE4B抑制剂选择性的起源.首先,探索了模拟时间、溶质介电常数、配体的电荷方案和结合自由能的计算方法对结合自由能预测值准确度的影响,确定最佳模拟条件为:模拟时间40~50 ns,溶质介电常数ε=2,采用MM/GBSA方法以及RESP配体电荷计算方案.接着,通过能量分解分析了抑制剂A33与PDE4B/PDE4D的相互作用,发现PDE4B酶上的Ile410、Gln443、Phe446和Phe506对抑制剂的选择性识别贡献较大.最后,通过位点突变方法探索了PDE4B的CR3螺旋上的Leu502残基对A33选择性所起的作用.当前的工作为设计高活性、高选择性的PDE4B抑制剂提供了有价值的结构与活性关系信息.