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Rahardjo HE, Ückert S, Maerker V, Bannowsky A, Kuczyk MA, Kedia GT. STIMULATION OF THE CYCLIC AMP/GMP SIGNALLING ENHANCES THE RELAXATION OF ISOLATED HUMAN DETRUSOR SMOOTH MUSCLE ACHIEVED BY PHOSPHODIESTERASE INHIBITORS. Georgian Med News 2021:7-12. [PMID: 34103422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Phosphodiesterase (PDE) enzymes are considered being key proteins in controlling the function of smooth musculature in the human urinary tract. The use of PDE inhibitors (PDE-Is) to treat erectile dysfunction and lower urinary tract symptomatology (LUTS) secondary to benign prostatic hyperplasia (BPH) is well established. It has been shown that PDE-Is can reverse the tension induced by means of muscarinergic agents of detrusor smooth muscle and enhance the production of cyclic nucleotides. In clinical settings, the PDE1 inhibitor vinpocetine had beneficial effects in patients presenting with voiding dysfunctions. This prompted us to evaluate further the mechanism of action of PDE-Is on bladder smooth musculature. Using the tissue bath technique, relaxant responses of human detrusor smooth muscle, challenged by acetylcholine (1 µM), to vinpocetine (PDE1-I), rolipram (PDE4-I), MY 5445 and sildenafil (PDE5-Is) (0.1 µM, 1 µM, and 10 µM) were investigated with and without pre-exposure of the tissue to threshold concentrations of the NO donor drug sodium nitroprusside (SNP) or adenylyl cyclase activator forskolin (0.02 µM). The non-specific PDE-I papaverine was used as a reference compound. The cumulative addition of forskolin or SNP exerted a pronounced reversion of the tension induced by means of ACh, starting at a concentration of 1 µM (forskolin, -25,6%) and 0.1 µM (SNP, -20%), respectively. There were marginal responses of the detrusor smooth musculature to the PDE-Is, the relaxation measured ranged from -12% (vinpocetine/sildenafil) to -19% (rolipram, MY 5445). Exposure of the tissue to a threshold concentration of SNP increased the reversion of tension induced by vinpocetine (-40%), rolipram (-50%) and MY 5445 (-45%). An enhancement in the potency of the drugs was also registered. A threshold concentration of SNP did not significantly affect the maximum reversion of tension brought about by sildenafil but added positively to the in vitro potency of the PDE5-I. PDE inhibitors may tend to be more effective in systems characterized by an enhanced production of cyclic AMP/GMP (such as urogenital tissues in vivo). Our findings may explain how PDE inhibitors can affect symptoms of the overactive bladder.
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Affiliation(s)
- H E Rahardjo
- 1University of Indonesia, School of Medicine, Cipto Mangunkusumo Hospital, Department of Urology, Jakarta, Indonesia
| | - S Ückert
- 2Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology, Germany
| | - V Maerker
- 3University Hospital Eppendorf, Department of Forensic Psychiatry, Institute for Sex Research, Hamburg, Germany
| | - A Bannowsky
- 4Imland Hospital GmbH, Department of Urology, Rendsburg, Germany
| | - M A Kuczyk
- 2Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology, Germany
| | - G T Kedia
- 2Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology; 5DIAKOVERE GmbH, Friederikenstft Lutheran Hospital, Department of Urology, Hannover, Germany
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Rahardjo HE, Ückert S, Bannowsky A, Kuczyk MA, Kedia GT. Expression of Phosphodiesterase (PDE) Isoenzymes in the Human Male and Female Urethra. Res Rep Urol 2021; 13:139-145. [PMID: 33777854 PMCID: PMC7989682 DOI: 10.2147/rru.s291962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/18/2021] [Indexed: 11/23/2022] Open
Abstract
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.
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Affiliation(s)
- Harrina E Rahardjo
- Department of Urology, Universitas Indonesia School of Medicine, Cipto Mangunkusumo Hospital, Jakarta, Indonesia.,Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology, Hannover, Germany
| | - Stefan Ückert
- Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology, Hannover, Germany
| | | | - Markus A Kuczyk
- Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology, Hannover, Germany
| | - George T Kedia
- Hannover Medical School, Division of Surgery, Department of Urology & Urological Oncology, Hannover, Germany.,DIAKOVERE GmbH, Friederikenstift Lutheran Hospital, Department of Urology, Hannover, Germany
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Kedia GT, Ückert S, Tsikas D, Becker AJ, Kuczyk MA, Bannowsky A. The Use of Vasoactive Drugs in the Treatment of Male Erectile Dysfunction: Current Concepts. J Clin Med 2020; 9:jcm9092987. [PMID: 32947804 PMCID: PMC7564459 DOI: 10.3390/jcm9092987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 09/04/2020] [Accepted: 09/10/2020] [Indexed: 12/11/2022] Open
Abstract
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.
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Affiliation(s)
- George T. Kedia
- Department of Urology & Urological Oncology, Division of Surgery, Hannover Medical School, 30625 Hannover, Germany; (G.T.K.); (S.Ü.)
- Department of Urology, DIAKOVERE GmbH, Friederikenstft Lutheran Hospital, 30171 Hannover, Germany
| | - Stefan Ückert
- Department of Urology & Urological Oncology, Division of Surgery, Hannover Medical School, 30625 Hannover, Germany; (G.T.K.); (S.Ü.)
| | - Dimitrios Tsikas
- Center of Pharmacology & Toxicology, Core Unit Proteomics, Hannover Medical School, 30625 Hannover, Germany;
| | - Armin J. Becker
- Faculty of Medicine, Academic Hospital Grosshadern, Department of Urology, Ludwig Maximilians University, 81377 Munich, Germany;
| | - Markus A. Kuczyk
- Department of Urology & Urological Oncology, Division of Surgery, Hannover Medical School, 30625 Hannover, Germany; (G.T.K.); (S.Ü.)
- Correspondence: ; Tel.: +49-(0)511-532-3437; Fax: +49-(0)511-532-3684
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Ückert S, Kedia GT, Tsikas D, Simon A, Bannowsky A, Kuczyk MA. Emerging drugs to target lower urinary tract symptomatology (LUTS)/benign prostatic hyperplasia (BPH): focus on the prostate. World J Urol 2019; 38:1423-1435. [PMID: 31506747 DOI: 10.1007/s00345-019-02933-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 08/28/2019] [Indexed: 01/07/2023] Open
Abstract
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.
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Affiliation(s)
- Stefan Ückert
- Division of Surgery, Department of Urology and Urological Oncology, Hannover Medical School, 30623, Hannover, Germany.
| | - George T Kedia
- Division of Surgery, Department of Urology and Urological Oncology, Hannover Medical School, 30623, Hannover, Germany
| | - Dimitrios Tsikas
- Core Unit Proteomics, Center of Pharmacology and Toxicology, Hannover Medical School, Hannover, Germany
| | - Annika Simon
- Department of Internal Medicine, Hannover Medical School, Hannover, Germany
| | | | - Markus A Kuczyk
- Division of Surgery, Department of Urology and Urological Oncology, Hannover Medical School, 30623, Hannover, Germany
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Rahardjo HE, Ückert S, Tsikas D, Hedlund P, Bannowsky A, Kuczyk MA, Kedia GT. Arginase enzymes in the human prostate: A molecular biological and immunohistochemical approach. Andrologia 2019; 51:e13349. [PMID: 31482616 DOI: 10.1111/and.13349] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 04/25/2019] [Accepted: 05/14/2019] [Indexed: 01/05/2023] Open
Abstract
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.
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Affiliation(s)
- Harrina E Rahardjo
- School of Medicine, Department of Urology, Cipto Mangunkusumo Hospital, University of Indonesia, Jakarta, Indonesia
| | - Stefan Ückert
- Department of Urology & Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany
| | - Dimitrios Tsikas
- Center of Pharmacology & Toxicology, Core Unit Proteomics, Hannover Medical School, Hannover, Germany
| | - Petter Hedlund
- Department of Clinical Pharmacology, Faculty of Medicine, Linköping University, Linköping, Sweden
| | | | - Markus A Kuczyk
- Department of Urology & Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany
| | - George T Kedia
- Department of Urology & Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany
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Kedia GT, Ückert S, Oelke M, Sonnenberg JE, Sohn M, Kuczyk MA, Hedlund P. Expression and distribution of phosphodiesterase isoenzymes in the human male urethra. Urology 2015; 85:964.e1-6. [PMID: 25704994 DOI: 10.1016/j.urology.2014.12.030] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 12/02/2014] [Accepted: 12/19/2014] [Indexed: 11/30/2022]
Abstract
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.
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Affiliation(s)
- George T Kedia
- Department of Urology and Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany.
| | - Stefan Ückert
- Department of Urology and Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany; Urological Research Unit, Institute for Biochemical Research and Analysis, Barsinghausen am Deister, Germany
| | - Matthias Oelke
- Department of Urology and Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany
| | - Joachim E Sonnenberg
- Urological Research Unit, Institute for Biochemical Research and Analysis, Barsinghausen am Deister, Germany
| | - Michael Sohn
- Department of Urology, AGAPLESION Markus Hospital, Frankfurt am Main, Germany
| | - Markus A Kuczyk
- Department of Urology and Urological Oncology, Division of Surgery, Hannover Medical School, Hannover, Germany
| | - Petter Hedlund
- Urological Research Institute, University Vita Salute San Raffaele, Milano, Italy; Department of Clinical Pharmacology, Faculty of Medicine, Linköping University, Linköping, Sweden
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Kedia GT, Oelke M, Sonnenberg JE, Sohn M, Bannowsky A, Kuczyk MA, Ückert S. Phosphodiesterase isoenzymes in the human urethra: A molecular biology and functional study. Eur J Pharmacol 2014; 741:330-5. [DOI: 10.1016/j.ejphar.2014.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Revised: 07/29/2014] [Accepted: 08/10/2014] [Indexed: 10/24/2022]
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Albrecht K, Kedia GT, Ückert S, Hagemeier L, Kuczyk MA, Klintschar M. [Induratio penis plastica and the capability of vaginal penetration in the context of forensic evaluation]. Georgian Med News 2014:89-93. [PMID: 25341246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The so-called Induratio penis plastica (IPP), also known as Peyronie Disease or Morbus Peyronie, is the most common cause for deviation of the male penis. In most cases, the deviation is directed to the dorsal side. In face of a lawsuit related to a sexual offence, the opponent might argue that, due to an existing IPP, he is generally unable to insert his penis into a female's vagina. The aim of the present study was to examine the clinical files of thirty (30) consecutive patients who presented with IPP. Particular attention was given to the individual degree of penile deviation and the ability of the subjects to conduct vaginal intercourse. Subjects who had a dorsal penile deviation of 800 to 900, or a lateral deviation of 600, were unable to commence vaginal coitus. In contrast, three (3) subjects who presented with a ventral deviation of 30° to 40° had no difficulties in performing vaginal penetration. The medicolegal aspects of these findings are being discussed.
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Affiliation(s)
- K Albrecht
- Institute of Legal Medicine, Hannover Medical School, Germany; Department of Urology and Urological Oncology, Hannover Medical School, Germany
| | - G T Kedia
- Institute of Legal Medicine, Hannover Medical School, Germany; Department of Urology and Urological Oncology, Hannover Medical School, Germany
| | - S Ückert
- Institute of Legal Medicine, Hannover Medical School, Germany; Department of Urology and Urological Oncology, Hannover Medical School, Germany
| | - L Hagemeier
- Institute of Legal Medicine, Hannover Medical School, Germany; Department of Urology and Urological Oncology, Hannover Medical School, Germany
| | - M A Kuczyk
- Institute of Legal Medicine, Hannover Medical School, Germany; Department of Urology and Urological Oncology, Hannover Medical School, Germany
| | - M Klintschar
- Institute of Legal Medicine, Hannover Medical School, Germany; Department of Urology and Urological Oncology, Hannover Medical School, Germany
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Kedia GT, Oelke M, Sohn M, Kuczyk MA, Ückert S. Pharmacologic characterization of human male urethral smooth muscle: an in vitro approach. Urology 2014; 82:1451.e13-9. [PMID: 24295263 DOI: 10.1016/j.urology.2013.08.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/15/2013] [Accepted: 08/09/2013] [Indexed: 10/26/2022]
Abstract
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.
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Affiliation(s)
- George T Kedia
- Division of Surgery, Department of Urology and Urological Oncology, Hannover Medical School, Hannover, Germany.
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Kedia GT, Uckert S, Assadi-Pour F, Kuczyk MA, Albrecht K. Avanafil for the treatment of erectile dysfunction: initial data and clinical key properties. Ther Adv Urol 2013; 5:35-41. [PMID: 23372609 DOI: 10.1177/1756287212466282] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
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.
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Affiliation(s)
- George T Kedia
- Department of Urology and Urological Oncology, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany
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Kedia GT, Sonnenberg JE, Kuczyk MA, Ückert S. Arginase enzymes in the human prostate: expression of arginase isoenzymes and effects of arginase inhibitors on isolated human prostate tissue. BJU Int 2012; 110:E1196-201. [DOI: 10.1111/j.1464-410x.2012.11529.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kedia GT, Ückert S, Polat H, Merseburger AS, Kuczyk MA. Evaluating the significance of cyclic adenosine monophosphate-mediated signaling in human prostate: a functional and biochemical study. Urology 2012; 80:952.e9-14. [PMID: 22901823 DOI: 10.1016/j.urology.2012.05.039] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 05/03/2012] [Accepted: 05/29/2012] [Indexed: 10/28/2022]
Abstract
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.
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Affiliation(s)
- George T Kedia
- Division of Surgery, Department of Urology and Urological Oncology, Hannover Medical School, Hannover, Germany.
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Uckert S, Kedia GT, Satzger I, Geismar U, Sohn M, Kuczyk MA, Hedlund P, Waldkirch ES. C-kit-positive multipolar cells in human penile erectile tissue: expression of connexin 43 and relation to trabecular smooth muscle cells. Georgian Med News 2010:13-19. [PMID: 20413811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The aim of this study was to evaluate the hypothesis that interstitial cells might play a role in controlling and synchronizing via gap junctions the electrical activity of smooth muscle cells. The expression and distribution of interstitial cells in human penile erectile tissue was evaluated to determine whether or not cavernous interstitial cells express the gap junction protein connexin 43. Specimens of human corpus cavernosum were excised from full preparations of human penises. Cryostat sections (10 microm to 15 microm) of formaldehyde-fixated tissue segments were incubated using a double-labelling technique with antibodies directed against smooth muscle alpha-actin, c-kit, and connexin 43. Then, sections were exposed to secondary antibodies. Visualization was commenced by means of laser fluorescence microscopy. Double-staining techniques revealed immunosignals specific for c-kit (transmembrane receptor protein) and connexin 43 (gap junction protein) in multipolar cells located adjacent to smooth muscle cells. The number of c-kit-positive cells was significantly lower within the smooth musculature than within bundles of connective tissue surrounding smooth muscle cells of corpus cavernosum or cavernous arteries. Our findings demonstrate the distribution of c-kit- and connexin 43-positive interstitial cells in the connective tissue and smooth musculature of the corpus cavernosum. Additional studies are needed in order to evaluate further the ultrastructure of human penile erectile tissue and enable the identification of gap junctions mediating direct cell-to-cell communication.
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Affiliation(s)
- S Uckert
- Hannover Medical School, Division of Surgery, Department of Urology and Urological Oncology, Hannover, Germany
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Birowo P, Uckert S, Kedia GT, Sonnenberg JE, Thon WF, Rahardjo D, Kuczyk MA. Characterization of the effects of various drugs likely to affect smooth muscle tension on isolated human seminal vesicle tissue. Urology 2009; 75:974-8. [PMID: 19969333 DOI: 10.1016/j.urology.2009.09.034] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2009] [Revised: 08/03/2009] [Accepted: 09/12/2009] [Indexed: 11/18/2022]
Abstract
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.
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Affiliation(s)
- Ponco Birowo
- Department of Urology, University of Indonesia School of Medicine, Cipto Mangunkusumo Hospital, Jakarta, Indonesia
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Birowo P, Uckert S, Kedia GT, Scheller F, Meyer M, Taher A, Rahardjo D, Jonas U, Kuczyk MA. Evaluating the role of the serotoninergic system in the control of human seminal vesicle smooth muscle-an in vitro approach. J Sex Med 2009; 6:2672-9. [PMID: 19686430 DOI: 10.1111/j.1743-6109.2009.01423.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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.
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Affiliation(s)
- Ponco Birowo
- Department of Urology & Uro-Oncology, Hannover Medical School, Hannover 30625, Germany
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Kedia GT, Neumayer E, Scheller F, Kuczyk MA, Uckert S. [In vitro effects of a novel class of nitric oxide donating compounds on isolated human urinary bladder]. Georgian Med News 2009:7-16. [PMID: 19276460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nitric oxide (NO) has been identified an important neurotransmitter involved in the control of the human urinary tract. It has been suggested that NO is one of the factors keeping the bladder relaxed during the filling phase. This function might be mediated by the NO-induced elevation of intracellular cyclic GMP. Prostaglandins (PG) are known to exert contractile effects on the bladder smooth musculature, especially in pathological conditions. The aim of the present study was to examine the effects of a new class of NO donor drugs, combining both anti-phlogistic and NO-donating activity (NCX 2111 and HCT 1026), on the contraction induced by PG or electrical field stimulation (EFS) of isolated human detrusor. Effects were compared to those of sodium nitroprusside (SNP), forskolin, tolterodine, and oxybutynin. Using the organ bath technique, drug effects on the contraction induced by PG ((F2 alpha)) or EFS of isolated human detrusor smooth muscle were investigated. Detrusor strips were also exposed to increasing concentrations of the compounds (0.1 microM - 10 microM) and the accumulation of cyclic GMP and cyclic AMP was determined by means of radioimmunoassays. The tension induced by PG was dose-dependently reversed by the drugs. The rank order of efficacy was: forskolin > SNP > NCX 2111 > HCT 1026. R(max) values ranged from 57% (forskolin) to 24% (HCT 1026). Compounds also dose-dependently reduced the amplitudes of contraction induced by EFS (tolterodine > oxybutynin > NNP = forskolin > HCT 1026 > 2111). The effects of forskolin, HCT 1026, NCX 2111 and SNP were paralleled by an increase in cyclic AMP or cyclic GMP. Our results provide evidence that the NO-cGMP pathway is not of utmost significance in the control of human detrusor smooth muscle. In vitro, the combination of NO-donating with anti-phlogistic activity does not seem to be of functional advantage with regard to the facilitation of detrusor relaxation.
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Affiliation(s)
- G T Kedia
- Hannover Medical School, Department of Urology and Uro-Oncology, Hannover, Germany
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