[Urinary incontinence after radical prostatectomy for prostate cancer-data from 17,149 patients from 125 certified centers]. / Harninkontinenz nach radikaler Prostatektomie beim Prostatakarzinom ­ aktuelle Daten von 17.149 Patienten aus 125 zertifizierten Zentren.

BACKGROUND: In addition to erectile dysfunction, urinary incontinence is the most common functional limitation after radical prostatectomy (RPE) for prostate cancer (PCa). The German S3 guideline recommends informing patients about possible effects of the therapy options, including incontinence. However, only little data on continence from routine care in German-speaking countries after RPE are currently available, which makes it difficult to inform patients. OBJECTIVE: The aim of this work is to present data on the frequency and severity of urinary incontinence after RPE from routine care. MATERIALS AND METHODS: Information from the PCO (Prostate Cancer Outcomes) study is used, which was collected between 2016 and 2022 in 125 German Cancer Society (DKG)-certified prostate cancer centers in 17,149 patients using the Expanded Prostate Cancer Index Composite Short Form (EPIC-26). Changes in the "incontinence" score before (T0) and 12 months after RPE (T1) and the proportion of patients who used pads, stratified by age and risk group, are reported. RESULTS: The average score for urinary incontinence (value range: 0-worst possible to 100-best possible) was 93 points at T0 and 73 points 12 months later. At T0, 97% of the patients did not use a pad, compared to 56% at T1. 43% of the patients who did not use a pad before surgery used at least one pad a day 12 months later, while 13% use two or more. The proportion of patients using pads differs by age and risk classification. CONCLUSION: The results provide a comprehensive insight into functional outcome 12 months after RPE and can be taken into account when informing patients.

Expression of Phosphodiesterase (PDE) Isoenzymes in the Human Male and Female Urethra.

PURPOSE: Although it has been supposed that the NO/cyclic GMP system produces inhibitory signals to reduce the resistance of the bladder outlet and urethra during the micturition phase, little is known on the mechanisms controlling the function of urethral smooth muscle. The aim of the present study was to examine in the male and female urethra the expression of phosphodiesterase (PDE) isoenzymes, known as key proteins of the cyclic GMP/AMP signaling. METHODS: Urethral tissue was obtained from 4 female cadavers and 7 male patients (who had undergone gender reassignment surgery). The expression of mRNA encoding for PDE1A, 1B, 1C, 2A, 4B, 4D, 5A, 10A and 11A was investigated by means of real-time polymerase chain reaction. Western blot (WB) analysis was conducted to detect PDE isoenzymes. RESULTS: RT-PCR revealed relevant amounts of mRNA encoding for PDE1A, 2A, 4B, 5A, 10A and 11A in male and female urethral tissue. The expression of PDE1A, 2A, 4B and 10A was 2-fold higher in the female than in the male urethra, whereas the expression of PDE11A mRNA was 7-fold higher in the male tissue. In the WB experiments, immunosignals specific for PDE1A, PDE4A and 4B and PDE11A were of higher degree in the female than the male tissue specimens, while an almost equivocal expression of PDE2A, PDE5A and PDE10A was registered. CONCLUSION: On the level of mRNA and function proteins, different patterns of expression of PDE isoenzymes were registered in human male and female urethra. Future studies may clarify whether inhibition of PDE isoenzymes is likely to facilitate the relaxation of the outflow region in both sexes.

The Use of Vasoactive Drugs in the Treatment of Male Erectile Dysfunction: Current Concepts.

It is widely accepted that disorders of the male (uro)genital tract, such as erectile dysfunction (ED) and benign diseases of the prostate (lower urinary tract symptomatology or benign prostatic hyperplasia), can be approached therapeutically by influencing the function of both the vascular and non-vascular smooth muscle of the penile erectile tissue or the transition zone/periurethral region of the prostate, respectively. As a result of the discovery of nitric oxide (NO) and cyclic guanosine monophosphate (GMP) as central mediators of penile smooth muscle relaxation, the use of drugs known to increase the local production of NO and/or elevate the intracellular level of the second messenger cyclic GMP have attracted broad attention in the treatment of ED of various etiologies. Specifically, the introduction of vasoactive drugs, including orally active inhibitors of the cyclic GMP-specific phosphodiesterase (PDE) 5, has offered great advantage in the pharmacotherapy of ED and other diseases of the genitourinary tract. These drugs have been proven efficacious with a fast on-set of action and an improved profile of side-effects. This review summarizes current strategies for the treatment of ED utilizing the application of vasoactive drugs via the oral, transurethral, topical, or self-injection route.

Emerging drugs to target lower urinary tract symptomatology (LUTS)/benign prostatic hyperplasia (BPH): focus on the prostate.

OBJECTIVES: The benign prostatic syndrome, comprising lower urinary tract symptomatology secondary to benign prostatic hyperplasia/enlargement, represents a major health care issue in westernized countries. The pharmacological management involves alpha-adrenoceptor antagonists, intervention into the hormonal control of prostate growth using inhibitors of the enzyme 5-alpha-reductase, and stimulation of the nitric oxide/cyclic GMP pathway by tadalafil, an inhibitor of the phosphodiesterase type 5. METHODS: This review summarizes the achievements which have been made in the development of drug candidates assumed to offer opportunities as beneficial treatment options in the management of the benign prostatic syndrome. RESULTS: A review of the literature has revealed that the line of development is focusing on drugs interfering with peripheral neuromuscular/neuronal mechanisms (nitric oxide donor drugs, agonists/antagonists of endogenous peptides, botulinum toxin, NX-1207), the steroidal axis (cetrorelix) or the metabolic turn-over (lonidamine), as well as the combination of drugs already established in the treatment of lower urinary tract symptomatology/benign prostatic hyperplasia (phosphodiesterase 5 inhibitor plus alpha-adrenoceptor antagonist). CONCLUSION: Many research efforts have provided the basis for the development of new therapeutic modalities for the management of lower urinary tract dysfunctions, some of which might be offered to the patients in the near future.

Arginase enzymes in the human prostate: A molecular biological and immunohistochemical approach.

The nitric oxide (NO) pathway plays a role in maintaining the function of the prostate. An impairment in the activity of the NO system may have an impact in the manifestation of lower urinary tract symptomatology and benign prostatic hyperplasia. Arginase enzymes (Arg) counteract the generation of NO by depleting the intracellular pool of L-arginine, known to be the substrate of the NO synthases. This study investigated the expression of arginase type I and II in the human prostate. Nondiseased prostate tissue was obtained during pelvic surgeries (prostatectomy, cystoprostatectomy). Tissue sections were exposed to antibodies directed against Arg I and II, cGMP, the phosphodiesterase 5 and nNOS. The expression of mRNA transcripts encoding for Arg I and Arg II was investigated using molecular biology. Reverse transcriptase polymerase chain reaction (RT-PCR) revealed the presence of mRNA encoding for Arg I and II, immunofluorescence specific for Arg I was seen in the stromal smooth musculature, and labelling for PDE5 and cyclic GMP was also observed. Nerve fibres containing nNOS were identified running across the smooth musculature. Immunostainings for Arg II did not yield signals. These findings are in support of the notion that, in the prostate, Arg is involved in the modulation of the activity of the NO system.

S-Nitroso-N-acetyl-L-cysteine ethyl ester (SNACET) and N-acetyl-L-cysteine ethyl ester (NACET)-Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, H2S and GSH suppliers and as antioxidants: Results and overview.

S-Nitrosothiols or thionitrites with the general formula RSNO are formally composed of the nitrosyl cation (NO+) and a thiolate (RS-), the base of the corresponding acids RSH. The smallest S-nitrosothiol is HSNO and derives from hydrogen sulfide (HSH, H2S). The most common physiological S-nitrosothiols are derived from the amino acid L-cysteine (CysSH). Thus, the simplest S-nitrosothiol is S-nitroso-L-cysteine (CysSNO). CysSNO is a spontaneous potent donor of nitric oxide (NO) which activates soluble guanylyl cyclase to form cyclic guanosine monophosphate (cGMP). This activation is associated with multiple biological actions that include relaxation of smooth muscle cells and inhibition of platelet aggregation. Like NO, CysSNO is a short-lived species and occurs physiologically at concentrations around 1 nM in human blood. CysSNO can be formed from CysSH and higher oxides of NO including nitrous acid (HONO) and its anhydride (N2O3). The most characteristic feature of RSNO is the S-transnitrosation reaction by which the NO+ group is reversibly transferred to another thiolate. By this way numerous RSNO can be formed such as the low-molecular-mass S-nitroso-N-acetyl-L-cysteine (SNAC) and S-nitroso-glutathione (GSNO), and the high-molecular-mass S-nitrosol-L-cysteine hemoglobin (HbCysSNO) present in erythrocytes and S-nitrosol-L-cysteine albumin (AlbCysSNO) present in plasma at concentrations of the order of 200 nM. All above mentioned RSNO exert NO-related biological activity, but they must be administered intravenously. This important drawback can be overcome by lipophilic charge-free RSNO. Thus, we prepared the ethyl ester of SNAC, the S-nitroso-N-acetyl-L-cysteine ethyl ester (SNACET), from synthetic N-acetyl-L-cysteine ethyl ester (NACET). Both NACET and SNACET have improved pharmacological features over N-acetyl-L-cysteine (NAC) and S-nitroso-N-acetyl-L-cysteine (SNAC), respectively, including higher oral bioavailability. SNACET exerts NO-related activities which can be utilized in the urogenital tract and in the cardiovascular system. NACET, with high oral bioavailability, is a strong antioxidant and abundant precursor of GSH, unlike its free acid N-acetyl-L-cysteine (NAC). Here, we review the chemical and pharmacological properties of SNACET and NACET as well as their analytical chemistry. We also report new results from the ingestion of S-[15N]nitroso-N-acetyl-L-cysteine ethyl ester (S15NACET) demonstrating the favorable pharmacological profile of SNACET.

S-Nitroso-N-acetyl-L-cysteine ethyl ester (SNACET) and N-acetyl-L-cysteine ethyl ester (NACET)–Cysteine-based drug candidates with unique pharmacological profiles for oral use as NO, H2S and GSH suppliers and as antioxidants: Results and overview / 药物分析学报

S-Nitrosothiols or thionitrites with the general formula RSNO are formally composed of the nitrosylcation(NO+)and a thiolate(RS-),the base of the corresponding acids RSH.The smallest S-nitrosothiol isHSNO and derives from hydrogen sulfide(HSH,H2S).The most common physiological S-nitrosothiols arederived from the amino acid L-cysteine(CysSH).Thus,the simplest S-nitrosothiol is S-nitroso-L-cysteine(CysSNO).CysSNO is a spontaneous potent donor of nitric oxide(NO)which activates soluble guanylylcyclase to form cyclic guanosine monophosphate(cGMP).This activation is associated with multiplebiological actions that include relaxation of smooth muscle cells and inhibition of platelet aggregation.Like NO,CysSNO is a short-lived species and occurs physiologically at concentrations around 1 nM inhuman blood.CysSNO can be formed from CysSH and higher oxides of NO including nitrous acid(HONO)and its anhydride(N2O3).The most characteristic feature of RSNO is the S-transnitrosation reaction bywhich the NO+group is reversibly transferred to another thiolate.By this way numerous RSNO can beformed such as the low-molecular-mass S-nitroso-N-acetyl-L-cysteine(SNAC)and S-nitroso-glutathione(GSNO),and the high-molecular-mass S-nitrosol-L-cysteine hemoglobin(HbCysSNO)present in erythrocytesand S-nitrosol-L-cysteine albumin(AlbCysSNO)present in plasma at concentrations of theorder of 200 nM.All above mentioned RSNO exert NO-related biological activity,but they must be administeredintravenously.This important drawback can be overcome by lipophilic charge-free RSNO.Thus,we prepared the ethyl ester of SNAC,the S-nitroso-N-acetyl-L-cysteine ethyl ester(SNACET),fromsynthetic N-acetyl-L-cysteine ethyl ester(NACET).Both NACET and SNACET have improved pharmacologicalfeatures over N-acetyl-L-cysteine(NAC)and S-nitroso-N-acetyl-L-cysteine(SNAC),respectively,including higher oral bioavailability.SNACET exerts NO-related activities which can be utilized in theurogenital tract and in the cardiovascular system.NACET,with high oral bioavailability,is a strong antioxidantand abundant precursor of GSH,unlike its free acid N-acetyl-L-cysteine(NAC).Here,we reviewthe chemical and pharmacological properties of SNACET and NACET as well as their analytical chemistry.We also report new results from the ingestion of S-[15N]nitroso-N-acetyl-L-cysteine ethyl ester(S15NACET)demonstrating the favorable pharmacological profile of SNACET.

Expression and distribution of phosphodiesterase isoenzymes in the human male urethra.

OBJECTIVE: To investigate the expression and distribution of phosphodiesterase (PDE) isoenzymes PDE1A, PDE2A, PDE4A, PDE4B, and PDE5A in human urethral tissue. METHODS: Specimens of penile urethra were obtained from male subjects who had undergone male-to-female sex reassignment surgery. Using immunohistochemistry (immunofluorescence), the occurrence of PDE1A, PDE2A, PDE4A, PDE4B, and PDE5A, the neuronal nitric oxide synthase, calcitonin gene-related peptide, and vasoactive intestinal polypeptide was examined in urethral sections. Cytosolic supernatants prepared from isolated human urethral tissue were subjected to Western blot analysis using specific anti-PDE antibodies. RESULTS: Immunosignals specific for PDE1A, 4A, 4B, and 5A were observed in the urethral smooth musculature. The smooth muscle bundles were seen innervated by slender nerve fibers, characterized by the expression of the neuronal nitric oxide synthase, calcitonin gene-related peptide, and vasoactive intestinal polypeptide. The expression of the PDE isoenzymes mentioned was confirmed by Western blotting. CONCLUSION: The results provide evidence for a significance of both the cyclic adenosine monophosphate and cyclic guanosine monophosphate signaling in the control of human urethral smooth muscle. The selective inhibition of PDE isoenzymes might represent a pharmacologic option to influence the function of smooth musculature in the human outflow region.

Phosphodiesterase isoenzymes in the human urethra: a molecular biology and functional study.

Experimental and clinical studies have suggested a role for phosphodiesterase (PDE) isoenzymes in the control of the human lower urinary tract. This study aimed to investigate the expression of PDE isoenzymes and the effects of PDE inhibitors (PDE-Is) in isolated human urethral smooth muscle (USM). The expression of messenger ribonucleic acid (mRNA) specifically encoding for PDE isoenzymes and isoforms (1A, 1B, 1C, 2A, 4A, 4B, 4C, 4D, 5A and 11A) was analyzed by means of reverse transcriptase polymerase chain reaction (RT-PCR). Using a tissue bath technique, the effects of vinpocetine (PDE1-I), erythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride (EHNA-HCl=MEP1) (PDE2-I), rolipram (PDE4-I), sildenafil, vardenafil and tadalafil (PDE5-Is) (0.01-10µM) on the tension of USM induced by norepinephrine were investigated. The production of cyclic guanosine monophosphate (cyclic GMP) and cyclic adenosine monophosphate (cyclic AMP) was measured by means of radioimmunoassays. RT-PCR analysis revealed the expression of PDE1B, PDE1C, PDE4A, PDE4C, PDE4D, PDE5A and PDE11A. The tension induced by norepinephrine (NE) was reversed by the PDE inhibitors with the following rank order of efficacy: rolipram (mean: -39%)≥sildenafil (-35%)>vardenafil (-26%)>tadalafil (-20%)>vinpocetine (-16%)>MEP1 (-2%). The relaxing effects of the drugs were paralleled by an elevation in tissue levels of cyclic AMP and cyclic GMP. Selective inhibitors of PDE4 and PDE5 can antagonize the tension induced by alpha-adrenergic stimulation of USM. PDE inhibition might represent an interesting option to facilitate the relaxation of the human outflow region.

Pharmacologic characterization of human male urethral smooth muscle: an in vitro approach.

OBJECTIVE: To elucidate the functional responses of isolated human urethral smooth muscle to various agents known to exert smooth muscle contraction or relaxation. METHODS: Specimens of penile urethra were obtained from male patients who had undergone male-to-female gender reassignment surgery. Using the tissue bath technique, the contraction induced by increasing concentrations (1 nM-10 µM) of norepinephrine, phenylephrine, acetylcholine, carbachol, prostaglandin F2α, endothelin 1, angiotensin II, and oxytocin was measured. In another set-up, the effects of C-type natriuretic peptide (0.1 nM-1 µM), sodium nitroprusside, sildenafil, forskolin, alpha2-antagonist delquamine, and acetylcholine (1 nM/10 nM-10 µM) on the tension induced by norepinephrine were investigated. The production of cyclic guanosine monophosphate (GMP) and cyclic adenosine monophosphate (AMP) was measured by means of specific radioimmunoassays. RESULTS: Endothelin 1, oxytocin, prostaglandin F2α, norepinephrine, and phenylephrine induced dose-dependent contraction of the isolated urethral tissue, whereas acetylcholine, carbachol, and angiotensin II had no or only minor contractile effects. The contraction induced by norepinephrine was reversed by the drugs with the following rank order of efficacy: sodium nitroprusside > delquamine > sildenafil > C-type natriuretic peptide > forskolin > acetylcholine. The maximal reversion of tension ranged from 68% (sodium nitroprusside) to 22% (acetylcholine). The relaxing effects of the drugs were paralleled by a several-fold increase in tissue levels of cyclic GMP and cyclic adenosine monophosphate. CONCLUSION: The results provide evidence that urethral smooth muscle is under the control of endogenous compounds, such as adrenergic agonists (norepinephrine and phenylephrine), vasoactive peptides, prostagladins, NO/cyclic GMP, and acetylcholine, assumed to influence micturition at the peripheral level.

Avanafil for the treatment of erectile dysfunction: initial data and clinical key properties.

Orally active, selective inhibitors of phosphodiesterase type 5 (PDE 5, cyclic GMP PDE), such as sildenafil, tadalafil and vardenafil, are currently the first-choice treatment options for the clinical management of erectile dysfunction (ED) of various etiologies and severities. However, a significant number of patients remain dissatisfied with the available therapies due a lack of efficacy or discomfort arising from adverse events. Several new PDE5 inhibitors, among which are avanafil (TA-1790), lodenafil, mirodenafil, udenafil, SLX-2101, JNJ-10280205 and JNJ-10287069, have recently been approved and introduced into the market or are in the final stages of their clinical development. Avanafil (marketed in the US under the brand name STENDRA(™)) has been developed by VIVUS Inc. (Mountain View, CA, USA) and has recently received approval from the US Food and Drug Administration (FDA) for use in the treatment of male ED. The drug has demonstrated improved selectivity for PDE5, is rapidly absorbed after oral administration with a fast onset of action and a plasma half-life that is comparable to sildenfil and vardenafil. In phase II and phase III clinical trials that included a large number of patients, avanafil has been shown to be effective and well tolerated. Owing to its favorable pharmacodynamic and pharmacokinetic profile, avanafil is considered as a promising new option in the treatment of ED. The present article summarizes the initial data and clinical key properties of avanafil.

Arginase enzymes in the human prostate: expression of arginase isoenzymes and effects of arginase inhibitors on isolated human prostate tissue.

UNLABELLED: What's known on the subject? and What does the study add? A previous study by Lexander et al. in 2005, using two-dimensional gel electrophoresis, demonstrated the expression of arginase type II in the different anatomical regions of the prostate; however, to date, no study has addressed, using an in vitro approach, the role of arginase isoenzymes in the human prostate. The results of the present study demonstrate that: both arginase isoenzymes, Arg I and Arg II, are expressed in the transition zone of the human prostate; the inhibition of arginase antagonized, to a certain degree, the tension brought about by noradrenaline in isolated human prostate tissue; exposure of human prostate tissue to arginase inhibitors enhanced the local production of cyclic GMP; and inhibition of arginase enzymes in the human prostate may augment the activity of the nitric oxide/cyclicGMP pathway. OBJECTIVE: • To investigate the expression of arginase isoenzymes type I (Arg I) and type II (Arg II) in the transition zone of the human prostate and the functional significance of arginase enzymes in the control of prostate smooth muscle. MATERIALS AND METHODS: • Human prostate tissue was obtained from male patients who had undergone pelvic surgery. • The expression of Arg I and Arg II was investigated using Western blot analysis. • Using the organ bath technique, the effects of cumulative administration of difluoromethylornithine (DFMO), H-Orn-OH × HCl, H-Ile-OH and N-ω-hydroxy-nor-L-arginine (nor-NOHA; 1 nM-10 µM) on the tension induced by noradrenaline in isolated prostate tissue were assessed. • Tissue strips were also exposed to arginase inhibitors and the production of cyclic GMP was determined. RESULTS: • Western blot analysis showed the expression of Arg I and Arg II in the transition zone of the prostate. • The tension induced by noradrenaline was antagonized by the drugs in the following rank order of efficacy: H-Orn-OH × HCl ≥ H-Ile-OH ≥ DFMO > nor-NOHA; however, the maximum reversion of tension recorded ranged from only -25 to -13%. • The enhancement in cyclic GMP production registered in the presence of the arginase inhibitors ranged from four- to 14-fold. CONCLUSIONS: • Arg I and Arg II are expressed in the transition zone of the human prostate. • Isometric tension studies and measurement of cyclic GMP showed that inhibition of arginase can reverse, to a certain degree, the tension of human prostate tissue induced by the activation of α-adrenoceptors and enhance the accumulation of cyclic GMP. • Future studies should explore further the role of arginase enzymes in the relaxation mediated by nitric oxide in prostate smooth muscle.

Evaluating the significance of cyclic adenosine monophosphate-mediated signaling in human prostate: a functional and biochemical study.

OBJECTIVE: To investigate further the potential significance of the cyclic adenosine monophosphate (cAMP) pathway in the control of prostate smooth muscle. The cAMP pathway has been assumed to be an alternative pharmacologic target to treat dysfunctions of the human lower urinary tract. To date, only a few studies have addressed the physiologic relevance of cAMP signal transduction in the control of human prostate function. METHODS: Phosphodiesterase activity was isolated from microsomal fractions prepared from prostatic tissue and subjected to biochemical analysis. Using the organ bath technique, the effects of the phosphodiesterase type (PDE)4 inhibitors Ro 20-1724, rolipram, and RP 73401 on the tension induced by norepinephrine of isolated prostatic tissue were investigated and compared with the PDE5 inhibitor sildenafil and BAY 13-1197, a nitric oxide-independent activator of the soluble guanylyl cyclase. Statistical analysis was conducted using the Gosset t test. RESULTS: Biochemical analysis of the microsomal fraction revealed only a single peak of PDE activity that was sensitive to papaverine and the PDE4 inhibitors rolipram and Ro 20-1724. The tension induced by norepinephrine was reversed by the drugs with the following order of efficacy: Ro 20-1724, RP 73401, rolipram, sildenafil, and BAY 13-1197. Pre-exposure of the tissue to a threshold concentration (0.05 µM) of forskolin (adenlyl cyclase activator) increased the reversion of tension induced by rolipram and RP 73401 and the PDE5 inhibitor sildenafil. CONCLUSION: These results have provided evidence for the significance of cAMP signaling in the control of prostate smooth muscle.

Exposure of human seminal vesicle tissue to phosphodiesterase (PDE) inhibitors antagonizes the contraction induced by norepinephrine and increases production of cyclic nucleotides.

OBJECTIVES: To investigate further the role of phosphodiesterase (PDE) isoenzymes in the control of human seminal vesicle (SV) smooth muscle contractility, we examined the functional responses of isolated SV tissue to various PDE inhibitors. It has been suggested that the application of inhibitors of the PDE type 5 may facilitate SV smooth muscle relaxation and, subsequently, retard ejaculatory response. METHODS: Using the organ bath technique, strip preparations of human SV were exposed for 5 minutes to 1 µM of the PDE inhibitors milrinone (PDE3 inhibitor), rolipram, Ro 20-1724 (PDE4 inhibitors), and sildenafil (PDE5 inhibitor). Norepinephrine (NE, alpha agonist) was then added (0,1 µM, 1 µM, and 10 µM) and isometric responses were recorded. A contraction-response curve to NE in the absence of PDE inhibitors was also generated. Drug effects on the production of cyclic adenosine monophosphate (AMP) and cyclic guanosine monophosphate (GMP) were measured by means of radioimmunometric assays. RESULTS: The contraction induced by NE was effectively antagonized by 1 µM of rolipram (83.3% inhibition), Ro 20-1724 (72.3% inhibition), sildenafil (41.6% inhibition), and milrinone (37.5% inhibition). The inhibition of force generation was paralleled by a 1.6-fold to 2.8-fold increase in tissue cyclic AMP (induced by milrinone, rolipram, Ro 20-1724), and a 12-fold rise in cyclic GMP (induced by sildenafil). CONCLUSION: The findings demonstrate that PDE inhibitors can counteract the contraction of human SV mediated by alpha-adrenergic receptors and enhance levels of cyclic nucleotides. This might be of importance with regard to the identification of new options for the pharmacological treatment of premature ejaculation.

Characterization of the effects of various drugs likely to affect smooth muscle tension on isolated human seminal vesicle tissue.

OBJECTIVES: To investigate the effects of different classes of drugs on the isometric tension of isolated human seminal vesicle (SV) tissue. The contractility of human SV contributes to the process of seminal emission during ejaculation. Different endogenous compounds, such as serotonin (5-HT), adenosine triphosphate (ATP), and nitric oxide, have been suggested to be involved in the control of contraction and relaxation of human SV smooth muscle. However, only limited data are available regarding the effects of compounds known to affect smooth musculature on SV contractile activity. METHODS: Using the organ bath technique, the effects of increasing concentrations (10 nm-1 microm/10 microm) of norepinephrine (NE), phenylephrine, endothelin 1, ATP, and 5-HT on human SV tissue at basal tension were studied. In another set-up, SV strip preparations were preincubated with prazosin (alpha-adrenergic blocker), nifedipine and verapamil (Ca(2+)-channel blockers), 2-aminoethoxydiphenyl borate [inositol 1,4,5-trisphosphate (IP(3)) antagonist], cromakalim (K(+)-channel opener), or Y-27632 (ROK inhibitor) (1 microm each, for 10 minutes), followed by the application of NE (0.1 microM, 1 microM, and 10 microm). RESULTS: SV smooth muscle was most effectively contracted by NE (mean = 75% of calibrated scale), phenylephrine (mean = 82% of calibrated scale), and endothelin 1 (mean = 70% calibrated scale), whereas only minor responses to ATP (mean = 10.65% calibrated scale) and 5-HT (mean = 6.3% calibrated scale) were observed. The contraction induced by NE was significantly inhibited after pre-exposure of the tissue to prazosin (-92.4%), cromakalim (-83.7%), 2-aminoethoxydiphenyl borate (-43.1%), Y-27632 (-42.8%), and nifedipine (-32.7%). CONCLUSIONS: alpha-adrenoceptor antagonism, activation of potassium channels, and inhibition of Rho-kinase decrease the sympathetic contraction of SV smooth muscle. This might be of significance with regard to the identification of new pharmacologic avenues to affect the male ejaculatory system.

Evaluating the role of the serotoninergic system in the control of human seminal vesicle smooth muscle-an in vitro approach.

INTRODUCTION: It has been suggested that serotonin re-uptake inhibitors (SRIs) may retard the ejaculatory response by acting directly on the seminal vesicle (SV) and ductus deferens smooth muscle. However, until now, only a very few experimental studies have investigated such potential local (peripheral) effects. AIM: To elucidate the effects of serotonin (5-HT) and the SRIs clomipramine, fluoxetine and imipramine on the tension induced by norepinephrine (NE) of isolated human SV smooth muscle, as well as on the production of tissue cyclic AMP and cyclic GMP. MAIN OUTCOME MEASURES: To measure the inhibition exerted by serotonin and SRIs clomipramine, fluoxetine, and imipramine on the contractile response of isolated SV tissue. In addition, the effects of the drugs on the turn-over of cyclic nucleotides cAMP and cGMP were also elucidated. METHODS: The effects of the cumulative addition of serotonin and the SRIs clomipramine, fluoxetine and imipramine (1 nM-10 microM) on the tension induced by the alpha(1)-adrenoceptor agonist NE (10 microM) of SV strip preparations were studied using the organ bath technique. Cyclic AMP and cyclic GMP were measured by means of specific radioimmunoassays. RESULTS: The tension induced by NE was dose-dependently reversed by the drugs tested. The rank order of efficacy was: imipramine > or = fluoxetine > or = clomipramine > serotonin. Mean reversion of tension was measured between 66 +/- 6.6% and 52 +/- 6.6%. These effects were paralleled by a 1.3-fold to 2.7-fold increase in tissue cAMP in response to exposure to the drugs. In contrast, no significant enhancement in cGMP was noted. CONCLUSIONS: The findings, for the first time, present evidence that SRIs may antagonize the sympathetic contraction of SV smooth muscle via stimulation of tissue cyclic AMP.

Effects of phosphodiesterase inhibitors on contraction induced by endothelin-1 of isolated human prostatic tissue.

OBJECTIVES: To study the effects of selective phosphodiesterase (PDE) inhibitors on the contraction induced by endothelin-1 (ET-1) of isolated human prostatic tissue. METHODS: Using the organ bath technique, the effects of the cumulative addition of the PDE1 inhibitor vinpocetine, PDE2 inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine hydrochloride (EHNA), PDE4 inhibitor rolipram, and PDE5 inhibitors sildenafil, vardenafil, and tadalafil (1 nM to 10 microM) were investigated on the contraction brought about by the peptide ET-1 (1 microM) on normal human prostatic tissue isolated from the transition zone. In the present study, the nitric oxide donor drug sodium nitroprusside and adenylyl cyclase activator forskolin were used as reference compounds. RESULTS: ET-1 induced stable and long-lasting contraction of the isolated prostatic tissue. The tension induced by ET-1 was dose-dependently reversed by the drugs with the following rank order of efficacy: rolipram, forskolin, tadalafil, sodium nitroprusside, sildenafil, vinpocetine, vardenafil, EHNA. The maximal reversion of tension ranged from 67% (rolipram) to 20% (EHNA). CONCLUSIONS: Our results have provide additional evidence that the function of prostatic smooth muscle is under the control of peptidergic and cyclic nucleotide (cyclic guanosine monophosphate, cyclic adenosine monophosphate)-mediated pathways. This might give a rationale for the use of drugs interacting with cyclic guanosine monophosphate or cyclic adenosine monophosphate signaling, such as PDE inhibitors or nitric oxide donors, in the pharmacotherapy of the benign prostatic syndrome.

The nitric oxide pathway in the human prostate: clinical implications in men with lower urinary tract symptoms.

To date, there is an increasing interest in the nitric oxide (NO) pathway as a potential pharmacological target to treat male lower urinary tract symptomatology (LUTS). In the transition zone of the human prostate, a dense nitrinergic innervation has been shown of the fibromuscular stroma, glandular epithelium and blood vessels. The expression of key proteins of the NO pathway, such as the endothelial and neuronal nitric oxide synthase (eNOS, nNOS), cGMP-degrading phosphodiesterase type 5 (PDE5) and cGMP-binding protein kinase (cGK), has also been demonstrated. The hypothesis that an impaired NO/cGMP-signaling may contribute to the pathophysiology of benign prostatic hyperplasia (BPH) is supported by the results from randomized, placebo-controlled clinical studies, indicating that NO donor drugs and PDE5-inhibitors sildenafil, tadalafil and vardenafil may be useful to treat storage and voiding dysfunctions resulting from LUTS in men. Thus, given a potential role of the NO-pathway in the prostate and/or in other parts of lower urinary tract (e.g. bladder), the enhancement of the NO signaling by NO donor drugs, PDE5 inhibitors or activators of the soluble guanylyl cyclase (sGC) may represent a new therapeutic strategy for the treatment of LUTS. This review serves to focus on the role of NO and the NO-dependent signaling in the control of smooth muscle function in the human prostate. Results from clinical trials in men with LUTS/BPH are also discussed.

Effects of phosphodiesterase inhibitors on tension induced by norepinephrine and accumulation of cyclic nucleotides in isolated human prostatic tissue.

OBJECTIVES: To further evaluate the mechanism of action of phosphodiesterase (PDE) inhibitors on the human prostate, the effects of PDE4 and PDE5 inhibitors on the tension induced by norepinephrine (NE) and on the intracellular levels of cyclic nucleotides in isolated human prostatic tissue were investigated. METHODS: Using the organ bath technique, the effects of increasing concentrations (1 nM to 10 microM) of the PDE5 inhibitors sildenafil, tadalafil, and vardenafil and the PDE4 inhibitors rolipram and RP 73401 on the tension induced by NE (40 microM) of prostate strip preparations were investigated. The accumulation of cyclic guanosine monophosphate and cyclic adenosine monophosphate in response to drug exposure was determined by radioimmunoassays. RESULTS: The tension induced by NE was dose dependently reversed by the drugs with the following rank order of efficacy: tadalafil greater than RP 73401 greater than rolipram greater than or equal to vardenafil greater than sildenafil. The maximal reversion of tension values ranged from 52.3% (tadalafil) to 17% (sildenafil). Of the PDE inhibitors, only tadalafil induced a 50% reversion of the initial tension. The most prominent enhancement in tissue cyclic adenosine monophosphate was registered in response to RP 73401 (11-fold), and cyclic guanosine monophosphate levels were significantly elevated by tadalafil, vardenafil, and sildenafil (28-fold, 12-fold, and 3-fold, respectively). CONCLUSIONS: Our results have demonstrated that drugs interfering with the cyclic nucleotide-mediated pathways can reverse the tension induced by NE in isolated prostatic tissue and elevate cyclic adenosine monophosphate and cyclic guanosine monophosphate. Our findings serve to explain how PDE inhibitors can affect symptoms of lower urinary tract symptoms and benign prostatic hyperplasia.