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1.
J Physiol Biochem ; 77(4): 557-564, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34018097

ABSTRACT

Lipopolysaccharide (LPS) is a component of gram-negative bacteria wall that elicits inflammatory response in the host through the toll-like receptor 4 (TLR4) activation. In the lower urinary tract (LUT), bacteria-derived LPS has been associated with lower urinary tract symptoms (LUTS); however, little is known about the effects of LPS in the urethral smooth muscle (USM). In the present study, we evaluated the functional and molecular effects of LPS in mouse USM in vitro, focusing on the LPS-induced TLR4-signaling pathway. Male C57BL6/JUnib and TLR4 knockout mice (TLR4 KO) were used. The USM contraction was performed in the presence of LPS (62.5-500 µg/mL), indomethacin (10 µM), L-NAME (100 µM), and TAK 242 (1 µM). The RT-PCR assay for the IL-1ß, NF-kB, and COX-2 genes was also evaluated in the presence of LPS (125 µg/mL) and caspase 1 inhibitor (20 µM). Our results showed that LPS reduces mouse USM contraction elicited by phenylephrine and vasopressin. This LPS-induced urethral inhibitory effect was not reversed by the TLR4 inhibition or its absence in the TLR4 KO mice. Conversely, indomethacin (but not L-NAME) reversed the LPS-induced USM hypocontractility. Molecular protocols indicated upregulation of IL-1ß, NF-kß, and COX-2 mRNA upon LPS incubation, which were blunted by caspase 1 inhibition. Our data showed that LPS reduced mouse USM contraction independently of TLR4 activation, involving caspase 1 and IL1ß, NF-kB, and COX-2 gene overexpression. Therefore, this alternative pathway might be a valuable target to reduce the LPS-induced urethral dysfunction under infection and inflammatory conditions.


Subject(s)
Lipopolysaccharides , NF-kappa B , Animals , Cyclooxygenase 2/genetics , Cyclooxygenase 2/metabolism , Lipopolysaccharides/toxicity , Male , Mice , Muscle, Smooth/metabolism , NF-kappa B/genetics , NF-kappa B/metabolism , Signal Transduction
2.
Nitric Oxide ; 106: 9-16, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33122152

ABSTRACT

Vascular aging leads to structural and functional changes. Iliac arteries (IA) provide blood flow to lower urinary tract and pelvic ischemia has been reported as an important factor for bladder remodeling and overactivity. Dysfunction of the nitric oxide (NO)-cyclic guanosine monophosphate pathway (cGMP) is one factor involved in the development of lower urinary tract (LUT) disorders. Therefore, we hypothesized that ageing-associated LUT disorders is a consequence of lower cGMP productions due to an oxidation of soluble guanylate cylase (sGC) that results in local ischemia. In the present study IA from middle-aged and young rats were isolated and the levels of NO, reactive oxygen species (ROS), the gene expression of the enzymes involved in the NO-pathway and concentration-response curves to the soluble guanylate (sGC) stimulator (BAY 41-2272), sGC activator (BAY 58-2667), tadalafil, acetylcholine (ACh) and sodium nitroprusside (SNP) were determined. In IA from middle-aged rats the gene expression for endothelial nitric oxide synthase and the ROS were lower and higher, respectively than the young group. The relaxations induced by ACh and SNP were significantly lower in IA from middle-aged rats. In IA from middle-aged rats the mRNA expression of PDE5 was 55% higher, accompanied by lower relaxation induced by tadalafil. On the other hand, the gene expression for sGCα1 were similar in IA from both groups. Both BAY 41-2272 and BAY 58-2667 produced concentration-dependent relaxations in IA from both groups, however, the latter was 9-times more potent than BAY 41-2272 and produced similar relaxations in IA in both middle-aged and young groups. Yet, the sGC oxidant, ODQ increased the relaxation and the cGMP levels induced by BAY 58-2667. On the other hand, in tissues stimulated with SNP, tadalafil and BAY-2272, the intracellular levels of cGMP were lower in IA from middle-aged than young rats. In conclusion, our results clearly showed that the relaxations induced by the endothelium-dependent and -independent agents, by the PDE5 inhibitor and by sGC stimulator were impaired in IA from aged rats, while that induced by sGC activator was preserved. It suggests that sGC activator may be advantageous in treating ischemia-related functional changes in the lower urinary tract organs in situations where the NO levels are reduced.


Subject(s)
Iliac Artery/enzymology , Soluble Guanylyl Cyclase/metabolism , Acetylcholine/pharmacology , Aging , Animals , Benzoates/pharmacology , Cyclic GMP/metabolism , Cyclic Nucleotide Phosphodiesterases, Type 5/metabolism , Male , Nitric Oxide/metabolism , Nitroprusside/pharmacology , Pyrazoles/pharmacology , Pyridines/pharmacology , Rats, Wistar , Reactive Oxygen Species/metabolism , Tadalafil/pharmacology , Vasodilation/drug effects , Vasodilator Agents/pharmacology
3.
Am J Physiol Renal Physiol ; 315(3): F460-F468, 2018 09 01.
Article in English | MEDLINE | ID: mdl-29717937

ABSTRACT

Interstitial Cystitis/Bladder Pain Syndrome (IC/BPS) is a chronic inflammatory disease without consistently effective treatment. We investigate the role of toll-like receptor 4 (TLR4) on voiding dysfunction and inflammation in the cyclophosphamide (CYP)-induced mouse cystitis. Male C57BL/6 [wild-type, (WT)] and/or TLR4 knockout (TLR4-/-) mice were treated with an injection of CYP (300 mg/kg, 24 h) or saline (10 ml/kg). The pharmacological blockade of the TLR4 by resatorvid (10 mg/kg) was also performed 1 h prior CYP-injection in WT mice. Urodynamic profiles were assessed by voiding stain on filter paper and filling cystometry. Contractile responses to carbachol were measured in isolated bladders. In CYP-exposed WT mice, mRNA for TLR4, myeloid differentiation primary response 88, and TIR-domain-containing adapter-inducing interferon-ß increased by 45%, 72%, and 38%, respectively ( P < 0.05). In free-moving mice, CYP-exposed mice exhibited a higher number of urinary spots and smaller urinary volumes. Increases of micturition frequency and nonvoiding contractions, concomitant with decreases of intercontraction intervals and capacity, were observed in the filling cystometry of WT mice ( P < 0.05). Carbachol-induced bladder contractions were significantly reduced in the CYP group, which was paralleled by reduced mRNA for M2 and M3 muscarinic receptors. These functional and molecular alterations induced by CYP were prevented in TLR4-/- and resatorvid-treated mice. Additionally, the increased levels of inflammatory markers induced by CYP exposure, myeloperoxidase activity, interleukin-6, and tumor necrosis factor-alpha were significantly reduced by resatorvid treatment. Our findings reveal a central role for the TLR4 signaling pathway in initiating CYP-induced bladder dysfunction and inflammation and thus emphasize that TLR4 receptor blockade may have clinical value for IC/BPS treatment.


Subject(s)
Anti-Inflammatory Agents/pharmacology , Cyclophosphamide , Cystitis, Interstitial/prevention & control , Sulfonamides/pharmacology , Toll-Like Receptor 4/antagonists & inhibitors , Toll-Like Receptor 4/deficiency , Urinary Bladder/drug effects , Adaptor Proteins, Vesicular Transport/genetics , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Cystitis, Interstitial/chemically induced , Cystitis, Interstitial/genetics , Cystitis, Interstitial/metabolism , Disease Models, Animal , Inflammation Mediators/metabolism , Interleukin-6/metabolism , Male , Mice, Inbred C57BL , Mice, Knockout , Myeloid Differentiation Factor 88/genetics , Myeloid Differentiation Factor 88/metabolism , Peroxidase/metabolism , Receptor, Muscarinic M2/genetics , Receptor, Muscarinic M2/metabolism , Receptor, Muscarinic M3/genetics , Receptor, Muscarinic M3/metabolism , Signal Transduction/drug effects , Toll-Like Receptor 4/genetics , Tumor Necrosis Factor-alpha/metabolism , Urinary Bladder/metabolism , Urinary Bladder/physiopathology , Urination/drug effects , Urodynamics/drug effects
4.
Life Sci ; 179: 120-129, 2017 Jun 15.
Article in English | MEDLINE | ID: mdl-28487215

ABSTRACT

AIMS: Androgen deficiency has been implicated in urological complications of postmenopausal women. This study examined the effects of testosterone replacements on the lower urinary tract dysfunction in 4-month old ovariectomized (OVX) rats. MAIN METHODS: Sprague-Dawley female rats were OVX bilaterally. Three months later, rats received single intramuscular injections of testosterone undecanoate. Cystometric study, and bladder and urethra smooth muscle reactivities were evaluated. KEY FINDINGS: Ovariectomy reduced by 65% (p<0.05) the serum testosterone levels. Testosterone replacement at 5mg/kg restored serum hormone levels to baseline, whereas 10mg/kg produced 14-fold higher testosterone levels. OVX rats exhibited significant increases of body weight, perigonadal fat and blood pressure, and reduced uterus weight, but none of these parameters were changed by testosterone replacements. OVX rats exhibited micturition dysfunction characterized by increases of basal pressure, threshold pressure, voiding frequency and post-voiding pressure. In addition, the bladder contractions induced by electrical-field stimulation (EFS) and carbachol were significantly reduced, whereas angiotensin II-induced urethral contractions were significantly increased in OVX rats. Testosterone replacement at 10mg/kg (but not at 5mg/kg) dose fully normalized the in vivo micturition dysfunction, as well as the in vitro bladder and urethral alterations. Testosterone (10mg/kg) also significantly potentiated the bladder relaxations induced by the ß3-adrenoceptor agonist mirabegron. The protective effects of testosterone were not modified by concomitant treatment with the aromatase inhibitor letrozole (2.5mg/kg, 4weeks). SIGNIFICANCE: The improvement of micturition dysfunction by testosterone replacement suggests that androgen therapy might be of therapeutic benefit for urological complications associated with post-menopause.


Subject(s)
Androgens/administration & dosage , Muscle, Smooth/drug effects , Postmenopause , Testosterone/analogs & derivatives , Urination Disorders/drug therapy , Acetanilides/pharmacology , Androgens/pharmacology , Angiotensin II/pharmacology , Animals , Carbachol/pharmacology , Disease Models, Animal , Dose-Response Relationship, Drug , Female , Injections, Intramuscular , Letrozole , Muscle, Smooth/metabolism , Nitriles/pharmacology , Ovariectomy , Rats , Rats, Sprague-Dawley , Testosterone/administration & dosage , Testosterone/pharmacology , Thiazoles/pharmacology , Triazoles/pharmacology , Urethra/drug effects , Urethra/metabolism , Urination Disorders/etiology
5.
Neurourol Urodyn ; 36(6): 1511-1518, 2017 Aug.
Article in English | MEDLINE | ID: mdl-27794199

ABSTRACT

AIMS: To evaluate the effects of the beta-3 adrenoceptor agonist, mirabegron in a mouse model of detrusor overactivity induced by obesity. METHODS: C57BL/6 male mice were fed with standard chow or high-fat diet for 12 weeks. Lean and obese mice were treated orally with mirabegron (10 mg/kg/day) from the last 2 weeks of diet. Cystometric evaluations, functional assays, protein expression for phosphodiesterase type 4 (PDE4), and cyclic adenosine monophosphate (cAMP) measurement were carried out. RESULTS: In obese mice the body weight, epididymal fat mass, fasting glucose, and low-density lipoprotein (LDL) levels were higher (P < 0.001) than in the lean mice. A reduction of 34% and 54% and an increase of 35% in the epididimal fat, LDL, and HDL levels (P < 0.05), respectively, were observed in the obese group treated with mirabegron, whereas no changes were seen in the lipid profile from lean mice. Obese group showed irregular micturition pattern, characterized by significant increases in frequency and non-void contractions. Carbachol, potassium chloride, and electrical-field stimulation induced detrusor smooth muscle (DSM) contractions, which were greater in bladders from obese mice than from lean mice. Two-week treatment with mirabegron restored all the contractile response alterations in the DSM. Basal intracellular levels of cAMP were reduced (68%), whereas PDE4 protein expression was increased (54%) in bladder from obese mice. Mirabegron restored the cAMP levels in obese bladder, without changing the PDE4 expression. CONCLUSION: Mirabegron was able to completely restore the urinary alterations seen in the bladder from obese mice.


Subject(s)
Acetanilides/therapeutic use , Adrenergic beta-3 Receptor Agonists/therapeutic use , Cyclic AMP/metabolism , Muscle, Smooth/drug effects , Obesity/physiopathology , Thiazoles/therapeutic use , Urinary Bladder, Overactive/drug therapy , Acetanilides/pharmacology , Adrenergic beta-3 Receptor Agonists/pharmacology , Animals , Body Weight/drug effects , Carbachol/pharmacology , Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Obese , Muscle Contraction/drug effects , Muscle, Smooth/metabolism , Muscle, Smooth/physiopathology , Obesity/metabolism , Thiazoles/pharmacology , Urinary Bladder/drug effects , Urinary Bladder/metabolism , Urinary Bladder/physiopathology , Urinary Bladder, Overactive/metabolism , Urinary Bladder, Overactive/physiopathology , Urination/drug effects
6.
Neurourol Urodyn ; 36(3): 589-596, 2017 03.
Article in English | MEDLINE | ID: mdl-26999618

ABSTRACT

AIMS: Aging is highly associated with benign prostate hyperplasia (BPH). We investigated here the alterations of the contractile and relaxant machinery in prostates of middle-aged rats, focusing on the Rho-kinase, nitric oxide (NO)-soluble guanylyl cyclase (sGC), α1- and ß-adrenoceptor pathways. METHODS: Male Wistar young (3.5-month old) and middle-aged rats (10-month old) were used. Quantitative image analysis of prostates and functional assays evaluating the prostate contractions and relaxations were employed. Measurement of [3 H]-noradrenaline efflux, western blotting for α1 and ß1 sGC subunits, and cyclic nucleotide levels were carried out. RESULTS: Prostates of middle-aged rats showed significant increases in lumen and smooth muscle cells, but no alterations in the relative prostate weight were observed. In vivo, noradrenaline (10-7 -10-4 g/kg) produced greater prostatic contractions in middle-aged compared with control rats. Likewise, the in vitro contractions to phenylephrine (1 nM-100 µM) and α,ß-methylene ATP (1-10 µM) were greater in middle-aged rats. Electrical-field stimulation (EFS, 1-32 Hz) promoted higher [3 H]-noradrenaline efflux and prostate contractions in middle-aged rats. Reduced expressions of α1 and ß1 sGC subunits and diminished NO-mediated prostate relaxations in middle-age were observed. Isoproterenol-induced relaxations and cAMP levels were reduced in prostates of middle-aged rats. The Rho-kinase inhibitor fasudil (50 mg/kg, 2 weeks) normalized the prostate hypercontractility in middle-age rats. CONCLUSIONS: Prostate hypercontractility in middle-aging is associated with increased release of noradrenaline and Rho-kinase pathway, as well as with impairments of NO-sGC and ß-adrenoceptor pathways. Middle-aged rats are suitable to explore the enhanced prostatic tone in the absence of prostate overgrowth. Neurourol. Urodynam. 36:589-596, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Muscle Contraction/physiology , Muscle, Smooth/metabolism , Prostate/metabolism , Soluble Guanylyl Cyclase/metabolism , rho-Associated Kinases/metabolism , Animals , Electric Stimulation , Male , Muscle, Smooth/physiopathology , Norepinephrine/metabolism , Prostate/physiopathology , Rats , Rats, Wistar , Signal Transduction/physiology
7.
PLoS One ; 11(12): e0166291, 2016.
Article in English | MEDLINE | ID: mdl-27935981

ABSTRACT

BACKGROUND: Sickle cell disease patients display priapism that may progress to erectile dysfunction. However, little is known about the pathophysiological alterations of corpus cavernosum in sickle cell disease. OBJECTIVE: Thus, this study aimed to evaluate the functional and molecular alterations of sympathetic machinery and nitric oxide-cyclic guanosine monophosphate signaling pathway in Townes transgenic sickle cell disease mice. METHODS: Concentration-response curves to contractile (phenylephrine) and relaxant agents (acetylcholine and sodium nitroprusside) were obtained in corpus cavernosum strips from sickle and C57BL/6 (control) mice. Neurogenic contractions and nitrergic relaxations were obtained using electrical-field stimulation. Measurements of endothelial nitric oxide synthase (eNOS), neuronal nitric oxide synthase (nNOS), phosphodiesterase-5 (PDE5) and α1A-, α1B- and α1D-adrenoceptor mRNA expressions and reactive-oxygen species were performed. Tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expressions in cavernosal tissues were also measured. RESULTS: The neurogenic contractions were higher in the sickle cell disease group, in association with elevated tyrosine hydroxylase phosphorylated at Ser-31 and total tyrosine hydroxylase protein expression, as well as increased tyrosine hydroxylase mRNA expression. Likewise, phenylephrine-induced contractions were greater in the sickle mice, whereas α1A-, α1B- and α1D-adrenoceptor mRNA expression remained unchanged. Cavernosal relaxations to acetylcholine, sodium nitroprusside and EFS were higher in sickle mice, accompanied by decreased eNOS and nNOS, along with lower PDE5 mRNA expression. An increase of about 40% in reactive-oxygen species generation in corpus cavernosum from sickle mice was also detected. CONCLUSION: Our study shows that decreased nitric oxide bioavailability in erectile tissue due to increased oxidative stress leads to both sympathetic hyperactivity and dysregulation of nitric oxide signaling in corpus cavernosum from Townes sickle mice.


Subject(s)
Anemia, Sickle Cell/physiopathology , Oxidative Stress , Penis/physiopathology , Sympathetic Nervous System/physiopathology , Tyrosine 3-Monooxygenase/metabolism , Acetylcholine/pharmacology , Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/metabolism , Animals , Blotting, Western , Cyclic Nucleotide Phosphodiesterases, Type 5/genetics , Cyclic Nucleotide Phosphodiesterases, Type 5/metabolism , Dose-Response Relationship, Drug , Electric Stimulation , Gene Expression/drug effects , In Vitro Techniques , Male , Mice, Inbred C57BL , Mice, Transgenic , Nitric Oxide Synthase Type I/genetics , Nitric Oxide Synthase Type I/metabolism , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Nitroprusside/pharmacology , Penis/drug effects , Penis/innervation , Phosphorylation/drug effects , Reactive Oxygen Species/metabolism , Receptors, Adrenergic/genetics , Receptors, Adrenergic/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Tyrosine 3-Monooxygenase/genetics , Vasodilator Agents/pharmacology
8.
Eur J Pharmacol ; 788: 29-36, 2016 Oct 05.
Article in English | MEDLINE | ID: mdl-27316789

ABSTRACT

The objective of the present work was to evaluate whether oral intake with resveratrol ameliorates overactive bladder in high-fat fed mice. Male C57BL6 mice fed with standard chow or high-fat diet to induce obesity received a two-week therapy with resveratrol (100mg/kg, given as a daily gavage). Weight and metabolic profile, together with cystometry and in vitro bladder contractions were evaluated. Measurements of gp91phox and SOD1 mRNA expressions and reactive-oxygen species (ROS) in bladder tissues, and serum TBARS were performed. Obese mice exhibited increases in body weight and epididymal fat mass, which were significantly reduced by oral treatment with resveratrol. Cystometric study in obese mice showed increases in non-voiding contractions, post-voiding pressure and voiding frequency that were reversed by resveratrol treatment. Likewise, the in vitro bladder overactivity in response to electrical-field stimulation (80V, 1-32Hz) or carbachol (1nM to 10mM) were normalized by resveratrol. The gp91phox and SOD1 mRNA expressions in bladder tissues were markedly higher in obese mice compared with lean group. In addition, ROS levels in bladder tissues and serum lipid peroxidation (TBARS assay) were markedly higher in obese compared with lean mice, all of which were reduced by resveratrol treatment. In lean group, resveratrol had no effect in any parameter evaluated. Our results show that two-week therapy of obese mice with resveratrol reduces the systemic and bladder oxidative stress, and greatly ameliorated the cystometry alterations and in vitro bladder overactivity. Resveratrol treatment could be an option to prevent obesity-associated overactive bladder.


Subject(s)
Anti-Obesity Agents/pharmacology , Antioxidants/pharmacology , Obesity/complications , Stilbenes/pharmacology , Urinary Bladder, Overactive/complications , Urinary Bladder, Overactive/drug therapy , Administration, Oral , Animals , Anti-Obesity Agents/administration & dosage , Anti-Obesity Agents/therapeutic use , Antioxidants/administration & dosage , Antioxidants/therapeutic use , Body Weight/drug effects , Diet, High-Fat/adverse effects , Gene Expression Regulation, Enzymologic/drug effects , Male , Membrane Glycoproteins/genetics , Mice , Mice, Inbred C57BL , Muscle, Smooth/drug effects , Muscle, Smooth/metabolism , NADPH Oxidase 2 , NADPH Oxidases/genetics , Obesity/etiology , Oxidative Stress/drug effects , RNA, Messenger/genetics , RNA, Messenger/metabolism , Resveratrol , Stilbenes/administration & dosage , Stilbenes/therapeutic use , Superoxide Dismutase-1/genetics , Time Factors , Urinary Bladder/drug effects , Urinary Bladder/metabolism , Urinary Bladder, Overactive/genetics , Urinary Bladder, Overactive/metabolism
9.
Urology ; 94: 312.e9-312.e15, 2016 Aug.
Article in English | MEDLINE | ID: mdl-27131967

ABSTRACT

OBJECTIVE: To evaluate the inhibitory effect of soluble guanylate cyclase (sGC) stimulator, BAY 41-2272 (5-cyclopropyl-2-[1-(2-fluorobenzyl)- 1H-pyrazolo[3,4-b]pyridine-3-yl]pyrimidin-4-ylamine) or activator, BAY 60-2770 (4-({(4- carboxybutyl) [2- (5-fluoro-2-{[40-(trifluoromethyl) biphenyl- 4-yl]methoxy}phenyl)ethyl] amino}methyl)benzoic acid), in human and rabbit prostate smooth muscle contractility. MATERIALS AND METHODS: In rabbit or human prostate, contractions induced by electrical field stimulation or phenylephrine (PE) were carried out in the presence of sGC stimulator, BAY 41-2272, or sGC activator, BAY 60-2770. The potency (pEC50) and maximal response (Emax) values were determined. Immunohistochemistry analysis for sGC α1-subunit and quantification of intracellular levels of cyclic guanosine monophosphate (cGMP) were also performed. RESULTS: In rabbit prostate, BAY 60-2770 (30 and 300 nM) inhibited the contractions induced by PE and electrical field stimulation. The coincubation with sGC inhibitor, ODQ, produced greater inhibitions on PE-induced contractions in comparison with BAY 60-2770 alone, mainly due to greater cGMP accumulation (70- and 5.7-fold, respectively). BAY 41-2272 (300 nM) increased and decreased, respectively, cGMP levels and PE-induced contractions, but in the presence of ODQ these effects were reversed. In human prostate, immunohistochemistry analysis revealed the presence of sGC α1-subunit on the transition zone. BAY 60-2770 (300 nM) reduced significantly Emax induced by PE in human prostate. CONCLUSION: sGC activator seems to be a promising alternative to treat benign prostatic hyperplasia because it increases cGMP levels even when sGC is oxidized.


Subject(s)
Benzoates/pharmacology , Biphenyl Compounds/pharmacology , Hydrocarbons, Fluorinated/pharmacology , Muscle Contraction/drug effects , Prostate/drug effects , Prostate/physiology , Pyrazoles/pharmacology , Pyridines/pharmacology , Animals , Humans , Male , Rabbits
10.
Am J Physiol Renal Physiol ; 311(1): F85-93, 2016 07 01.
Article in English | MEDLINE | ID: mdl-27122537

ABSTRACT

Activators of soluble guanylyl cyclase (sGC) interact directly with its prosthetic heme group, enhancing the enzyme responsiveness in pathological conditions. This study aimed to evaluate the effects of the sGC activator BAY 58-2667 on voiding dysfunction, protein expressions of α1 and ß1 sGC subunits and cGMP levels in the bladder tissues after cyclophosphamide (CYP) exposure. Female C57BL/6 mice (20-25 g) were injected with CYP (300 mg/kg ip) to induce cystitis. Mice were pretreated or not with BAY 58-2667 (1 mg/kg, gavage), given 1 h before CYP injection. The micturition patterns and in vitro bladder contractions were evaluated at 24 h. In freely moving mice, the CYP injection produced reduced the micturition volume and increased the number of urine spots. Cystometric recordings in CYP-injected mice revealed significant increases in basal pressure, voiding frequency, and nonvoiding contractions (NVCs), along with decreases in bladder capacity, intercontraction interval, and compliance. BAY 58-2667 significantly prevented the micturition alterations observed in both freely moving mice and cystometry and normalized the reduced in vitro carbachol-induced contractions in the CYP group. Reduced protein expressions of α1 and ß1 sGC subunits and of cGMP levels were observed in the CYP group, all of which were prevented by BAY 58-2667. CYP exposure significantly increased reactive-oxygen species (ROS) generation in both detrusor and urothelium, and this was normalized by BAY 58-2667. The increased myeloperoxidase and cyclooxygenase-2 activities in the bladders of the CYP group remained unchanged by BAY 58-2667. Activators of sGC may constitute a novel and promising therapeutic approach for management of interstitial cystitis.


Subject(s)
Benzoates/therapeutic use , Cystitis/drug therapy , Cystitis/physiopathology , Enzyme Activators/therapeutic use , Soluble Guanylyl Cyclase/drug effects , Urinary Bladder/physiopathology , Alkylating Agents , Animals , Carbachol/pharmacology , Cyclic AMP/metabolism , Cyclooxygenase 2/metabolism , Cyclophosphamide , Cystitis/chemically induced , Edema/chemically induced , Edema/physiopathology , Edema/prevention & control , Mice , Mice, Inbred C57BL , Muscarinic Antagonists/pharmacology , Peroxidase/metabolism , Reactive Oxygen Species/metabolism , Urinary Bladder/metabolism
11.
Prostate ; 75(4): 440-7, 2015 Mar 01.
Article in English | MEDLINE | ID: mdl-25417911

ABSTRACT

BACKGROUND: Alpha1 (α1)-blockers, 5-alpha reductase and phosphodiesterase type-5 inhibitors are pharmacological classes currently available for benign prostatic hyperplasia (BPH) treatment. Mirabegron, a beta-3 adrenoceptor (ß3-AR) agonist has been approved for the therapy of overactive bladder and may constitute a new therapeutic option for BPH treatment. This study is aimed to evaluate the in vitro effects of mirabegron in human and rabbit prostatic smooth muscle. METHODS: In rabbit prostate, electrical field stimulation (EFS)-induced contraction and concentration-response curve (CRC) to mirabegron in phenylephrine pre-contracted tissues were carried out. The potency (pEC50 ) and maximal response (Emax ) values were determined. In human prostate, CRC to phenylephrine was carried out in the absence and presence of mirabegron. Immunohistochemistry analysis for ß3-AR was also carried out. RESULTS: In human prostate, immunohistochemistry analysis revealed the presence of ß3-AR on the transition zone and mirabegron reduced by 42% the phenylephrine-induced contractions. In rabbit prostate, mirabegron produced concentration-dependent relaxations (pEC50 : 6.01 ± 0.12; Emax : 106 ± 3%), which were fully resistant to the blockade of ß1-AR and ß2-AR. The ß3-AR blocker L748,337 caused a six-fold rightward shift in mirabegron-induced relaxations. Mirabegron (10 µM) reduced by 63% the EFS-induced contractions. Inhibitors of nitric oxide (L-NAME) and of soluble guanylate cyclase (ODQ) along with a cocktail of K+ channel blockers (apamin, charybdotoxin, glibenclamide, tetraethylammonium) all failed to significantly affect the mirabegron-induced rabbit relaxations. CONCLUSION: Mirabegron relaxes prostatic smooth muscle, providing an experimental support for the clinical investigation of its combination with an α1-blockers or PDE5 inhibitors in the treatment of BPH. Prostate 75:440-447, 2015. © 2014 Wiley Periodicals, Inc.


Subject(s)
Acetanilides/pharmacology , Adrenergic beta-3 Receptor Agonists/pharmacology , Muscle Relaxation/drug effects , Muscle, Smooth/drug effects , Prostate/drug effects , Thiazoles/pharmacology , Animals , Humans , Male , Rabbits
12.
J Pharmacol Exp Ther ; 349(1): 2-9, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24421320

ABSTRACT

Obesity has emerged as a major contributing risk factor for overactive bladder (OAB), but no study examined urethral smooth muscle (USM) dysfunction as a predisposing factor to obesity-induced OAB. This study investigated the USM relaxant machinery in obese mice and whether soluble guanylyl cyclase (sGC) activation with BAY 60-2770 [acid 4-({(4-carboxybutyl) [2-(5-fluoro-2-{[4-(trifluoromethyl) biphenyl-4-yl] methoxy} phenyl) ethyl] amino} methyl) benzoic] rescues the urethral reactivity through improvement of sGC-cGMP (cyclic guanosine monophosphate) signaling. Male C57BL/6 mice were fed for 12 weeks with a high-fat diet to induce obesity. Separate groups of animals were treated with BAY 60-2770 (1 mg/kg per day for 2 weeks). Functional assays and measurements of cGMP, reactive-oxygen species (ROS), and sGC protein expression in USM were determined. USM relaxations induced by NO (acidified sodium nitrite), NO donors (S-nitrosoglutathione and glyceryl trinitrate), and BAY 41-2272 [5-cyclopropyl-2-[1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-pyrimidin-4-ylamine] (sGC stimulator) were markedly reduced in obese compared with lean mice. In contrast, USM relaxations induced by BAY 60-2770 (sGC activator) were 43% greater in obese mice (P < 0.05), which was accompanied by increases in cGMP levels. Oxidation of sGC with ODQ [1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one] (10 µM) potentiated BAY 60-2770-induced USM responses in the lean group. Long-term oral BAY 60-2770 administration fully prevented the impairment of USM relaxations in obese mice. Reactive-oxygen species (ROS) production was enhanced, but protein expression of ß1 second guanylate cyclase subunit was reduced in USM from obese mice, both of which were restored by BAY 60-2770 treatment. In conclusion, impaired USM relaxation in obese mice is associated with ROS generation and down-regulation of sGC-cGMP signaling. Prevention of sGC degradation by BAY 60-2770 ameliorates the impairment of urethral relaxations in obese mice.


Subject(s)
Benzoates/therapeutic use , Biphenyl Compounds/therapeutic use , Enzyme Activators/therapeutic use , Guanylate Cyclase/metabolism , Hydrocarbons, Fluorinated/therapeutic use , Nitric Oxide/metabolism , Obesity/drug therapy , Receptors, Cytoplasmic and Nuclear/metabolism , Urethra/drug effects , Animals , Benzoates/administration & dosage , Biphenyl Compounds/administration & dosage , Dose-Response Relationship, Drug , Enzyme Activation , Enzyme Activators/administration & dosage , Hydrocarbons, Fluorinated/administration & dosage , Male , Mice , Mice, Inbred C57BL , Muscle Relaxation/drug effects , Muscle Tonus/drug effects , Muscle, Smooth/drug effects , Muscle, Smooth/enzymology , Muscle, Smooth/metabolism , Obesity/complications , Obesity/enzymology , Obesity/physiopathology , Reactive Oxygen Species/metabolism , Soluble Guanylyl Cyclase , Urethra/enzymology , Urethra/metabolism , Urinary Bladder, Overactive/enzymology , Urinary Bladder, Overactive/etiology , Urinary Bladder, Overactive/physiopathology , Urinary Bladder, Overactive/prevention & control
13.
Life Sci ; 93(22): 820-9, 2013 Nov 19.
Article in English | MEDLINE | ID: mdl-24050930

ABSTRACT

AIMS: The renin-angiotensin system (RAS) plays a major role in cardiovascular diseases in postmenopausal women, but little is known about its importance to lower urinary tract symptoms. In this study we have used the model of ovariectomized (OVX) estrogen-deficient rats to investigate the role of RAS in functional and molecular alterations in the urethra and bladder. MAIN METHODS: Responses to contractile and relaxant agents in isolated urethra and bladder, as well as cystometry were evaluated in 4-month OVX Sprague-Dawley rats. Angiotensin-converting enzyme activity and Western blotting for AT1/AT2 receptors were examined. KEY FINDINGS: Cystometric evaluations in OVX rats showed increases in basal pressure, capacity and micturition frequency, as well as decreased voiding pressure. Angiotensin II and phenylephrine produced greater urethral contractions in OVX compared with Sham group. Carbachol-induced bladder contractions were significantly reduced in OVX group. Relaxations of urethra and bladder to sodium nitroprusside and BAY 41-2272 were unaffected by OVX. Angiotensin-converting enzyme activity was 2.6-fold greater (p<0.05) in urethral tissue of OVX group, whereas enzyme activity in plasma and bladder remained unchanged. Expressions of AT1 and AT2 receptors in the urethra were markedly higher in OVX group. In bladder, AT1 receptors were not detected, whereas AT2 receptor expression was unchanged between groups. 17ß-Estradiol replacement (0.1mg/kg, weekly) or losartan (30 mg/kg/day) largely attenuated most of the alterations seen in OVX group. SIGNIFICANCE: Prolonged estrogen deprivation leads to voiding dysfunction and urethral hypercontractility that are associated with increased ACE activity and up-regulation of angiotensin AT1/AT2 receptor in the urethral tissue.


Subject(s)
Lower Urinary Tract Symptoms/etiology , Renin-Angiotensin System/physiology , Urethra/physiology , Urinary Bladder/physiopathology , Angiotensin II/pharmacology , Angiotensin II Type 1 Receptor Blockers/pharmacology , Animals , Carbachol/pharmacology , Dose-Response Relationship, Drug , Estradiol/pharmacology , Female , In Vitro Techniques , Losartan/pharmacology , Ovariectomy , Peptidyl-Dipeptidase A/metabolism , Phenylephrine/pharmacology , Pyrazoles/pharmacology , Pyridines/pharmacology , Rats , Rats, Sprague-Dawley , Receptor, Angiotensin, Type 1/metabolism , Receptor, Angiotensin, Type 2/metabolism , Renin-Angiotensin System/drug effects , Urethra/drug effects , Urinary Bladder/drug effects , Urinary Bladder/physiology , Urination , Vasoconstrictor Agents/pharmacology
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