| 1. |
|
|
| 2. |
- Gratzke, Christian, et al.
(författare)
-
Effects of cannabinor, a novel selective cannabinoid 2 receptor agonist, on bladder function in normal rats
- 2010
-
Ingår i: European Urology. - : Elsevier. - 0302-2838 .- 1873-7560. ; 57:6, s. 1093-1100
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Cannabinoid (CB) receptors may be involved in the control of bladder function; the role of CB receptor subtypes in micturition has not been established.OBJECTIVES: Our aim was to evaluate the effects of cannabinor, a novel CB2 receptor agonist, on rat bladder function.DESIGN, SETTING, AND PARTICIPANTS: Sprague Dawley rats were used. Distribution of CB2 receptors in sensory and cholinergic nerves of the detrusor was studied. Selectivity of cannabinor for human and rat CB receptors was evaluated. Effects of cannabinor on rat detrusor and micturition were investigated.MEASUREMENTS: Immunohistochemistry, radioligand binding, tritium outflow assays, organ bath studies of isolated bladder tissue, and cystometry in awake rats were used.RESULTS AND LIMITATIONS: CB2 receptor immunoreactivity was expressed in the urothelium and in sensory and cholinergic bladder nerves. Cannabinor exhibited similar binding at human and rat CB2 receptors and a 321-fold functional selectivity for the CB2 receptor versus the CB1 receptor. Cannabinor had no effect on isolated detrusor muscle function. In vivo, cannabinor 3.0mg/kg increased micturition intervals and volumes by 52% (p<0.05) and 96% (p<0.01), respectively, and increased threshold and flow pressures by 73% (p<0.01) and 49% (p<0.001), respectively. Cannabinor 0.3 or 1.0mg/kg or vehicle did not affect urodynamic parameters.CONCLUSIONS: Considering that CB2 receptors are localized on sensory nerves and on the urothelium and that cannabinor had effects on "afferent" urodynamic parameters, peripheral CB2 receptors may be involved in sensory functions of rat micturition. Effects of cannabinor on cholinergic nerve activity in normal bladder tissue appear to be limited.
|
|
| 3. |
- Gratzke, Christian, et al.
(författare)
-
Localization and Function of Cannabinoid Receptors in the Corpus Cavernosum: Basis for Modulation of Nitric Oxide Synthase Nerve Activity
- 2010
-
Ingår i: EUROPEAN UROLOGY. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 57:2, s. 342-348
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Anandamide, a proposed endogenous cannabinoid (CB) agonist, has been shown to enhance neurogenic responses in vitro of the rat corpus cavernosal tissue (CC). However, no information is available on the distribution of CB-receptors or effects by anandamide in CC from primates or humans. Objective: To characterize the distribution of CB-receptor isoforms in the human and primate CC and to investigate the effects of anandamide on isolated CC preparations. Design, setting, and participants: CC tissue was excised from the crura penis of six rhesus monkeys and five patients. Expression and distribution of CB1 and CB2 receptors were characterized with Western blot analyses and immunohistochemical investigations. The effects of anandamide on isolated CC preparations were analyzed during pharmacologic and nerve-mediated activation of primate tissue in aerated organ baths. Measurements: The expression and localization of CB1 and CB2 receptors in the primate CC and effects of anandamide on nerve-mediated relaxations and pharmacologically evoked contractions. Results and limitations: Western blot experiments revealed CB1 and CB2 receptors at expected band weights. Within and between strands of CC smooth muscle, CB1 and CB2 immunoreactivity (IR) was found in nerve fibers that also expressed IR for nitric oxide synthase (NOS) or transient receptor potential V1 (TRPV1). Neither CB1-IR nor CB2-IR nerves were colocalized with calcitoningene-related peptide (CGRP)-containing or tyrosine hydroxylase-containing nerves. No differences were observed between primate and human CC sections. Anandamide (10(-9) to 10(-4) M) had no contractile effects on CC smooth muscle, no relaxant effects on precontracted preparations, and no effect on phenylephrine-induced contractions. However, anandamide (10 mu M) inhibited electrically evoked smooth-muscle relaxations (34-48%; p andlt;= 0.05). Conclusions: CB1 and CB2 receptors are located on NOS-containing nerves in primate and human CC tissue. In contrast to findings in rats, anandamide antagonized nerve-mediated relaxations of the primate CC, suggesting important species differences for CB-mediated functions. The results also suggest a peripheral mechanism for cannabis-related sexual dysfunction.
|
|
| 4. |
- Gratzke, Christian, et al.
(författare)
-
Transient Receptor Potential A1 and Cannabinoid Receptor Activity in Human Normal and Hyperplastic Prostate: Relation to Nerves and Interstitial Cells
- 2010
-
Ingår i: EUROPEAN UROLOGY. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 57:5, s. 902-910
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Ion channel transient receptor potential A1 (TRPA1) and cannabinoid (CB) receptors are involved in mechanoafferent signaling from the bladder and the urethra. Objective: To characterize TRPA1-, CB1-, and CB2-receptor activities in the human prostate. Design, setting, and participants: Prostate specimens were obtained from 12 patients undergoing radical prostatectomy. We studied expressions (n = 6) of TRPA1, CB1, and CB2 receptors and effects of the TRPA1 agonists allyl isothiocyanate (AI), cinnamaldehyde (CA), sodium hydrogen sulfide (NaHS), and CP 55940 (a CB1/CB2 agonist) on prostatic preparations. Measurements: Western blot, immunohistochemistry, and functional experiments were performed. Results and limitations: Western blot detected expected bands for CB1, CB2, and TRPA1. TRPA1 immunoreactivity was located on nerves that were positive for CB1, CB2, calcitonin gene-related peptide (CGRP), nitric oxide synthase (NOS), or vesicular acetylcholine transporter (VAChT). CB1 and CB2 immunoreactivity was found on nerves that were positive for NOS, VAChT, or CGRP. Adrenergic nerves were not immunoreactive for TRPA1, CB1, or CB2. In nodular hyperplasia, nerves containing the above markers were scarce or absent. TRPA1 immunoreactivity was detected in cyclic guanosinemonophosphate-positive basal cells of the glandular epithelium. Basal or subepithelial TRPA1-immunoreactive cells contained vimentin and c-kit immunoreactivity. CA and NaHS relaxed precontracted preparations by 55 +/- 7% and 35 +/- 3% (n = 6 for each). CP 55940, NaHS, AI, capsaicin, and CA decreased nerve contractions up to 27%, 80%, 47%, and 87%, respectively (n = 6 for each). Conclusions: The distribution and function of TRPA1 and CB receptors in prostatic tissue suggest a role for these receptors in mechanoafferent signals, epithelial homeostasis, emission, or inflammation of the human prostate.
|
|
| 5. |
- Gratzke, Christian, et al.
(författare)
-
Transient Receptor Potential A1 (TRPA1) Activity in the Human Urethra-Evidence for a Functional Role for TRPA1 in the Outflow Region
- 2009
-
Ingår i: EUROPEAN UROLOGY. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 55:3, s. 696-704
-
Tidskriftsartikel (refereegranskat)abstract
- Background: A role for the transient receptor potential (TRP) A1 ion channel in rat lower urinary tract (LUT) sensation and disease has been proposed, but in the human LUT no information on TRPA1 activity is available. Objectives: To investigate the distribution of TRPA1 in the human urethra and to study the effect of TRPA1 agonists on isolated urethral strip preparations. Design, settings, and participants: Urethral specimens were obtained preoperatively from 10 patients and were freshly prepared for Western blot, immunohistochemistry, and functional in vitro investigations. Measurements: The expression patterns of TRPA1 were studied with Western blot and immunohistochemistry. The effects of allyl isothiocyanate (A1), cinnamaldehyde (CA), and NaHS (donor of H2S) on tension of urethral strips were investigated in tissue baths. Results and limitations: TRPA1 immunoreactivity (-IR) was found in nerve fibres in the suburothelial space and was also located to nerve fibres of the muscle layer. Single TRPA1-IR nerves extended into the urothelium. A majority, but not all TRPA1-IR nerves also expressed immunoreactivity for CGRP or TRPV1. In the urothelium, TRPV1 was located to the outer layers whereas TRPA1 was observed in basal urothelial cells. Interspersed between strands of smooth muscle cells of the urethral wall, TRPA1- and vimentin-IR cells containing central nuclei and slender cytoplasmatic extensions were observed. In functional experiments, TRPA1-agonists had no contractile effect in urethral preparations. After precontraction with phenylephrine, AI, CA, and NaHS caused concentration-dependent relaxations of urethral strip preparations.´ Conclusions: The localization of TRPA1 to nerves that also express TRPV1 and CGRP, and in urothelial cells and interstitial cells, as well as the findings that TRPA1 agonists can modify tone of urethral preparations, propose a role for TRPA1 in afferent and efferent sensory signaling of the human outflow region.
|
|
| 6. |
- Russo, Andrea, et al.
(författare)
-
Effects of the Gonadotropin-Releasing Hormone Antagonist Ganirelix on Normal Micturition and Prostaglandin E-2-Induced Detrusor Overactivity in Conscious Female Rats
- 2011
-
Ingår i: EUROPEAN UROLOGY. - : ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. - 0302-2838 .- 1873-7560. ; 59:5, s. 868-874
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Gonadotropin-releasing hormone (GnRH) antagonists have been reported to have beneficial effects on lower urinary tract symptoms in patients with benign prostatic hyperplasia. Objective: Our aim was to investigate the effects of ganirelix, a GnRH receptor antagonist, on bladder function and detrusor overactivity (DO) in female rats. Design, setting, and participants: Female Sprague-Dawley rats received 2 wk of daily systemic (0.1 mg/kg) or acute intravesical administration (IVES; 0.14 mg/l or 1.4 mg/l) ganirelix or vehicle (controls). Measurements: Assessments were obtained using cystometry in awake rats, organ bath studies, enzyme-linked immunosorbent assay, and western blot (WB). Results and limitations: Luteinising hormone levels were lower in rats treated systemically with ganirelix than in controls. No differences were observed in body or bladder weights. Micturition interval (MI), micturition volume (MV), residual volume, and bladder capacity (BC) were similar in both groups at baseline. No differences in urodynamic pressure parameters were observed between groups at baseline. Intravesical prostaglandin E-2 reduced MI, MV, and BC, and it increased basal pressure (BP), threshold pressure (TP), flow pressure (FP), and maximum pressure (MP) in all rats. MI, MV, and BC were reduced by 43% +/- 4%, 50% +/- 4%, and 43% +/- 4% (controls) versus 22% +/- 3%, 23% +/- 3%, and 21% +/- 3% (ganirelix-treated rats; p andlt; 0.001). TP and FP increased by 38% +/- 8% and 30% +/- 4% (controls) versus 16% +/- 7% and 16% +/- 5% (ganirelix; p andlt; 0.05). The maximal force of contractions for carbachol was larger in detrusor from ganirelix-treated rats (231% vs 177% of 60 mM K+-induced contractions). At 0.14 mg/l, but not 0.14 mg/l, IVES ganirelix increased MI, MV, and BC and decreased BP, TP, FP, and MP. In vitro, ganirelix had no effect on detrusor function. The gonadotropin-releasing hormone receptor was expressed (by WB) in the bladder mucosa. Conclusions: Systemic treatment with ganirelix counteracted experimental DO in female rats. Because bladder preparations from these rats exhibited larger contractions to carbachol and because intravesical ganirelix affected both micturition intervals and urodynamic pressure profiles, a peripheral site of action of ganirelix in the urinary bladder cannot be excluded.
|
|
| 7. |
- Streng, T., et al.
(författare)
-
Distribution and Function of the Hydrogen Sulfide-Sensitive TRPA1 Ion Channel in Rat Urinary Bladder
- 2008
-
Ingår i: European Urology. - : Elsevier BV. - 0302-2838 .- 1873-7560. ; 53:2, s. 391-400
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: To investigate the distribution of the transient receptor potential (TRP) A1 ion channel in the rat urinary bladder, and to study the effects of hydrogen sulfide (H2S) and known TRPA1 activators on micturition in conscious rats and on heterologously expressed ion channels. Methods: The expression of TRPA1 in urinary bladder was studied with fluorescence immunohistochemistry and real-time PCR in female Sprague-Dawley rats. Cystometric investigations were performed in conscious animals subjected to intravesical administration of sodium hydrogen sulfide (NaHS, donor of H2S), allyl isothiocyanate (AI), and cinnamaldehyde (CA). Fluorometric calcium imaging was used to study the effect of NaHS on human and mouse TRPA1 expressed in CHO cells. Results: TRPA1 immunoreactivity was found on unmyelinated nerve fibres within the urothelium, suburothelial space, and muscle layer as well as around blood vessels throughout the bladder. All TRPA1 immunoreactive nerves fibres also expressed TRPV1 immunoreactivity and vice versa. TRPA1 was also detected in urothelial cells at both transcriptional and protein levels. AI increased micturition frequency and reduced voiding volume. CA and NaHS produced similar changes in urodynamic parameters after disruption of the urothelial barrier with protamine sulfate. NaHS also induced calcium responses in TRPA1-expressing CHO cells, but not in untransfected cells. Conclusions: The expression of TRPA1 on C-fibre bladder afferents and urothelial cells together with the finding that intravesical TRPA1 activators initiate detrusor overactivity indicate that TRPA1 may have a role in sensory transduction in this organ. The study also highlights H2S as a TRPA1 activator potentially involved in inflammatory bladder disease. © 2007.
|
|
| 8. |
- Uckert, S, et al.
(författare)
-
Immunohistochemical distribution of cAMP- and cGMP-phosphodiesterase (PDE) isoenzymes in the human prostate
- 2006
-
Ingår i: European Urology. - : Elsevier BV. - 1873-7560 .- 0302-2838. ; 49:4, s. 740-745
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: With the introduction of sildenafil citrate (VIAGRA (TM)), the concept of phosphodiesterase (PDE) inhibition has gained tremendous interest in the field of urology. Cyclic nucleotide second messengers cGMP and cAMP have been assumed to be involved in the control of the normal function of the prostate. The aim of the present study was to evaluate by means of immunohistochemistry the expression and distribution of some cAMP- and cGMP-PDE isoenzymes in the prostate. Material & Methods: Cryostat sections (10 mu M) of form aldehyde-fixated tissue segments excised from the transition zone of human prostates were incubated with primary antibodies directed against the PDE isoenzymes 3, 4, 5, and 11. Then, sections were exposed to either fluorescein iso-thiocyanate- (FITC) or Texas Red- (TR) labeled secondary antibodies and visualization was commenced by means of laser fluorescence microscopy. Results: TR-immunofluorescence indicating the presence of PDE4 (cAMP-PDE) was abundantly observed in the fibromuscular stroma as well as in glandular structures of the transition zone. In contrast to the distribution of PDE4, immunoactivity indicating PDE5 (cGMP-PDE) and 11 (dual substrate PDE) was mainly observed in glandular and subglandular areas. No immunostaining for PDE3 (cGMP-inhibited PDE) was detected. Conclusion: Our results confirm the presence of PDE isoenzymes 4, 5 and 11 in the transition zone of the human prostate and present evidence that these isoenzymes are not evenly distributed. These findings are in support of the hypothesis that there might be a rationale for the use of PDE inhibitors in the pharmacotherapy of BPH and LUTS. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 9. |
- Ueckert, Stefan, et al.
(författare)
-
Update on phosphodiesterase (PDE) isoenzymes as pharmacologic targets in urology: Present and future
- 2006
-
Ingår i: European Urology. - : Elsevier BV. - 1873-7560 .- 0302-2838. ; 50:6, s. 1194-1207
-
Forskningsöversikt (refereegranskat)abstract
- Objectives & Methods: Diseases of the human urinary tract represent common morbidities characterized by a high prevalence in the population of most westernized countries. The existeince of a significant number of affected patients and the recent increase in scientific attention has resulted in various experimental and clinical efforts in order to evaluate the mechanisms controlling the function of urinary tract organs. This review attempts to describe the physiology and pharmacology of phosphodiesterase (PDE) isoenzymes with special regard to their (potential) use in disorders of the human urogenital tract. Results: The promising clinical data for the orally active phosphodiesterase (PDE) inhibitors sildenafil, vardenafil and tadalafil, used in the treatment of male erectile dysfunction (MED), has boosted research activities on the significance of the cyclic GMP- and cyclic AMP pathway in other genitourinary tract tissues, such as the bladder, prostate, ureter, urethra, as well as female genital tissues. Based on the more extensive understanding of the pathways controlling the function of the male and female urogenital tract, orally administered phosphodiesterase inhibitors are considered a logical and straightforward approach for treating urological diseases. Due to the unending charge to conceive advanced first-line treatments, new therapeutic options taking into consideration the cyclic nucleotide signaling have been introduced or might be launched in the near future. Upcoming strategies will not only focus on the nitric oxide (No)/cGMP cascade but also on compounds modulating signal transduction mediated by cyclic adenosine monophosphate, as well as combined agents in order to affect multiple peripheral intracellular targets. Conclusions: The article highlights cGMP- and cAMP-pathways, PDE subtypes and their present or putative future clinical significance in urological practice. (c) 2006 European Association of Urology. Published by Elsevier B.V. All rights reserved.
|
|
| 10. |
- Waldkirch, Eginhard S, et al.
(författare)
-
Immunohistochemical Distribution of Cyclic GMP-Dependent Protein Kinase-1 in Human Prostate Tissue.
- 2007
-
Ingår i: European Urology. - : Elsevier BV. - 1873-7560 .- 0302-2838. ; 52:2, s. 495-502
-
Tidskriftsartikel (refereegranskat)abstract
- Objectives: Phosphodiesterase 5 (PDE5) inhibitors improve smooth muscle relaxation and therefore are considered for pharmacotherapy of benign prostatic hyperplasia (BPH) and lower urinary tract symptoms (LUTS). Cyclic guanosine monophosphate (cGMP) -dependent protein kinase-1 (cGKI) has been identified as one of the downstream targets for cGMP. The aim of the present study was to evaluate, by means of immunohistochemistry and Western blot analysis, the expression and localization of cGKI isoforms in relation to smooth muscle alpha-actin and cGMP in the human prostate. Methods: Cryostat sections of tissue segments excised from the transition zone of human prostates from 11 patients (aged 54-68 yr) were incubated with primary antibodies directed against smooth muscle alpha-actin, cGMP, cGKI, c:GKI alpha, and cGKI beta. Visualization of double-labelled immunofluorescent staining was achieved by laser microscopy. Western blot analysis was performed to confirm the expression of cGKI isoforms. Results: Immunoreactivities specific for cGKI, cGKI alpha, and cGKI beta were observed in the smooth musculature of the transition zone. Double-staining revealed the colocalization of smooth muscle alpha-actin, cGMP, and cGKI isoforms in smooth muscle cells of the fibromuscular stroma. The expression of cGKI isoforms was confirmed by Western blot analysis. Conclusions: Our results confirm the presence of cGKI isoforms a and P in the transition zone of human prostate tissue. in addition, the colocalization of alpha-actin, cGMP, and cGKI isoforms provides further evidence for a significant role of the nitric oxide/cGMP pathway in the regulation of smooth muscle contractility in human prostate tissue and therefore could provide additional targets for pharmacotherapy of BPH and LUTS. (C) 2007 European Association of Urology. Published by Elsevier B.V. All rights reserved.
|
|
