Investigations into the presence of functional Beta1, Beta2 and Beta3-adrenoceptors in urothelium and detrusor of human bladder.

PURPOSE: We investigated the presence of functional Beta1, Beta2 and Beta3-adrenoceptor in urothelium and detrusor muscle of human bladder through in vitro pharmacology of selective Beta3 adrenoceptor agonist solabegron. MATERIALS AND METHODS: Expression of these adrenoceptors in surgically separated human urothelium and detrusor muscle were investigated using RT-PCR. The effects of activating these receptors were studied by determining the relaxation produced by Beta-adrenoceptors agonist in pre-contracted human detrusor strips. RESULTS: The results confirmed the presence of mRNA for Beta1, Beta2 and Beta3-adrenoceptor in both human urothelium and detrusor. In an in vitro functional bladder assay, Solabegron and other agonists for Beta-adrenoceptors such as procaterol and isoproterenol evoked potent concentration-dependent relaxation of isolated human bladder strips with pD2 values of 8.73 +/- 0.19, 5.08 +/- 0.48 and 6.28 +/- 0.54, respectively. CONCLUSIONS: Selective Beta3-adrenoceptor agonist may be a potential new treatment for the overactive bladder OAB syndrome. Existence of Beta3-adrenoceptor mRNA exists in the urothelium in addition to the detrusor muscle suggest multiple site of actions for the Beta3-adrenoceptor in the lower urinary tract.

Investigations into the presence of functional ß1, ß2 and ß3-adrenoceptors in urothelium and detrusor of human bladder

Purpose: We investigated the presence of functional ß1, ß2 and ß3-adrenoceptor in urothelium and detrusor muscle of human bladder through in vitro pharmacology of selective ß3 adrenoceptor agonist solabegron. Materials and Methods: Expression of these adrenoceptors in surgically separated human urothelium and detrusor muscle were investigated using RT-PCR. The effects of activating these receptors were studied by determining the relaxation produced by ß-adrenoceptors agonist in pre-contracted human detrusor strips. Results: The results confirmed the presence of mRNA for ß1, ß2 and ß3-adrenoceptor in both human urothelium and detrusor. In an in vitro functional bladder assay, Solabegron and other agonists for ß-adrenoceptors such as procaterol and isoproterenol evoked potent concentration-dependent relaxation of isolated human bladder strips with pD2 values of 8.73 ± 0.19, 5.08 ± 0.48 and 6.28 ± 0.54, respectively. Conclusions: Selective ß3-adrenoceptor agonist may be a potential new treatment for the overactive bladder OAB syndrome. Existence of ß3-adrenoceptor mRNA exists in the urothelium in addition to the detrusor muscle suggest multiple site of actions for the ß3-adrenoceptor in the lower urinary tract.

Human urine with solifenacin intake but not tolterodine or darifenacin intake blocks detrusor overactivity.

The objective of the study was to evaluate the local effects of three antimuscarinics excreted into human urine after oral ingestion. Two normal adult collected their voided urine after taking oral doses of tolterodine, darifenacin, and solifenacin for 7 days with a 14-day washout period. The urodynamic effect of intravesically administered human urine on carbachol-induced bladder overactivity was studied in female rats. Cystometric parameters were measured during continuous infusion of saline and human urine and then a mixture of carbachol (30 microM) and human urine. Carbachol significantly reduced the intercontraction interval and bladder capacity in the control (urine taken in the absence of oral antimuscarinics) and tolterodine- or darifenacin-administered groups. However, human urine obtained after taking solifenacin prevented the carbachol-induced detrusor overactivity. Urine excreted after oral ingestion of solifenacin provides a localized pharmacological advantage for the treatment of the overactive bladder syndrome.

(Z)-1,1-Dichloro-2-(4-methoxyphenyl)-3-phenylcyclopropane induces concentration-dependent growth inhibition, apoptosis, and coordinates regulation of apoptotic genes in TRAMP cells.

(Z)-1-1-Dichloro-2,3-diphenylcyclopropane (A(II)) and (Z)-1,1-dichloro-2-(4-methoxyphenyl)-3-phenylcyclopropane [2-(4-methoxyphenyl)-A(II)] inhibit tubulin polymerization, PSA production, and the proliferation of human prostate cancer cells. The actions of the agents were studied in three transgenic adenocarcinomas of the mouse prostate (TRAMP) cell lines. Antiproliferative potencies were determined and cells treated with the more potent 2-(4-methoxyphenyl)-A(II) were examined for induction of apoptosis. Microarray analyses were conducted to determine the apoptosis-related genes up- and down-regulated by the agent. 2-(4-Methoxyphenyl)-A(II) concentration-dependently inhibited growth of all three cell lines. Fifty percent and 100% growth inhibitory and 50% lethal concentrations were determined to be 0.3, 1.5, and 5 muM, respectively. Minimum detectable apoptosis-inducing concentrations by ELISA were 0.10 to 0.14 muM. PARP cleavage and two-color flow cytometry assays verified apoptosis induction. Microarray analyses showed Bok and Siva-pending to be up-regulated and that Birc, Dad1, and Atf5 were down-regulated. 2-(4-methoxyphenyl)-A(II) inhibits proliferation and induces apoptosis in the in vivo-adaptable TRAMP cells, suggesting the compound should be further examined in preclinical models.

Tubulin-perturbing naphthoquinone spiroketals.

Several natural and synthetic naphthoquinone spiroketals are potent inhibitors of the thioredoxin-thioredoxin reductase redox system. Based on the antimitotic and weak antitubulin actions noted for SR-7 ([8-(furan-3-ylmethoxy)-1-oxo-1,4-dihydronaphthalene-4-spiro-2'-naphtho[1'',8''-de][1',3'][dioxin]), a library of related compounds was screened for tubulin-perturbing properties. Two compounds, TH-169 (5'-hydroxy-4'H-spiro[1,3-dioxolane-2,1'-naphthalen]-4'-one) and TH-223 (5'-methoxy-4'H-spiro[1,3-dioxane-2,1'-naphthalen]-4'-one), had substantial effects on tubulin assembly and were antiproliferative at low micromolar concentrations. TH-169 was the most potent at blocking GTP-dependent polymerization of 10 mum tubulin in vitro with a remarkable 50% inhibitory concentration of ca. 400 nm. It had no effect on paclitaxel-induced microtubule assembly and did not cause microtubule hypernucleation. TH-169 failed to compete with colchicine for binding to beta-tubulin. The 50% antiproliferative concentration of TH-169 against human cancer cells was at or slightly below 1 mum. Flow cytometry showed that 1 mum TH-169 caused an increase in G(2)/M and hypodiploid cells. TH-169 eliminated the PC-3 cells' polyploid population and increased their expression of p21(WAF1) and Hsp70 in a concentration-dependent manner. The antiproliferative effect of TH-169 was irreversible and independent of changes in caspases, actin, tubulin, glyceraldehyde phosphate dehydrogenase or Bcl-x(S/L). This structurally simple naphthoquinone spiroketal represents a small molecule, tubulin-interactive agent with a novel apoptotic pathway and attractive biological function.

Effect of hyperforin-enriched extract on pro-ejaculatory effect of 8-hydroxy-2-(di-N-propylamino)tetralin in anesthetized rats.

OBJECTIVES: Premature ejaculation is the most common male sexual dysfunction and, yet, no approved effective therapies are currently available. We studied the in vivo effectiveness of hyperforin (HF), a concentrated extract of Hypericum perforatum in an experimental model for the expulsion phase of ejaculation in anesthetized rats. METHODS: The ejaculation model involved inducing rhythmic bulbospongiosus (BS) muscle contractions in male rats under urethane anesthesia (1.2 g/kg subcutaneously) by transiently raising the internal urethral pressure with saline infusion for 2 seconds at a rate of 116 microL/s. Electrodes in the BS muscles recorded the electrical activity during the contractions as a cluster of bursts on the electromyogram. Injection of the 5-hydroxytryptamine type 1A agonist 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT) (0.4 mg/kg subcutaneously) intensified the BS muscle contractions induced by increases in urethral pressure. RESULTS: Administration of 8-OH-DPAT strongly accelerated the ejaculation in the vehicle-treated rats and the amplitude of electrical discharges and the duration of electrical bursts accompanying the increases in urethral pressure were increased from baseline by 203.2% +/- 32.9% and 178.1% +/- 22.9%, respectively. The HF extract reduced the effects of 8-OH-DPAT on ejaculation at lower doses when tested in the dose range of 5 to 80 mg/kg. The reduction in the amplitude of bursts with HF extract remained unchanged after a midthoracic spinal transection, suggesting that the action of HF is either at the spinal ejaculation generator or directly on the neurons innervating the BS muscles. CONCLUSIONS: This is the first report of the effect of HF in a rat model of ejaculation. HF can be considered a novel new treatment of premature ejaculation.

The overactive bladder: Epidemiology and morbidity.

The International Continence Society recognizes the overactive bladder (OAB) as a "symptom syndrome suggestive of lower urinary tract dysfunction" that is defined as "urgency, with or without urge incontinence, usually with frequency and nocturia." Patients who have OAB are often sleep deprived and their sexual life is hindered. These patients have a restricted social life and an increased risk for depression. Accurate prevalence figures are difficult to obtain because most patients consider OAB an inevitable part of aging and some patients are too embarrassed to seek diagnosis. Primary care physicians need to be educated about the importance of identifying this clinical problem and managing it in a way that will minimize morbidity and maximize quality-of-life improvement. This article describes the various aspects of OAB, with special emphasis on epidemiology and morbidity.

The case for bladder botulinum toxin application.

Botulinum toxin (BoNT) has been shown to be and effective agent in suppressing detrusor overactivity due to neurogenic causes. Recently, BoNT has been extended to patients who have idiopathic detrusor overactivity. This article reviews the use of BoNT to treat disorders of neurogenic detrusor overactivity and establishes BoNT as a therapeutic modality to treat idiopathic bladder overactivity. It is important to remember that the application of BoNT in the lower urinary tract is not approved by the regulatory agencies and caution should be applied until larger randomized clinical studies are completed.

The promise of beta3-adrenoceptor agonists to treat the overactive bladder.

The detrusor muscle contains beta-adrenoceptors (beta-ARs), of which two subtypes--beta1-AR and beta2-AR--have been identified in most species. Although beta2-AR has an important role in muscle relaxation, evidence suggests that a third subtype--beta3-AR--mediates relaxation of human detrusor muscle. This article reviews the evidence for beta3-AR in human detrusor muscle and urothelium and discusses the potential use of beta3-AR agonists for the treatment of overactive bladder. In addition, the cAMP-dependent and -independent mechanisms of relaxation by way of beta-ARs in rat detrusor muscle, with and without pre-contraction, are reported. Finally, the consequences of mutation of a beta3-AR gene (relating to the pathophysiology of idiopathic detrusor instability) are discussed.

Botulinum A toxin for the treatment of benign prostatic hyperplasia/lower urinary tract symptoms.

Botulinum neurotoxin (BoNT) has been called the most poisonous poison and a potential bioterrorism weapon, and yet modern medicine has been able to harvest the elegant and specific activity of this toxin to treat a variety of medical conditions. BoNT application recently has been extended to prostate disorders, and this article reviews the literature on the mechanisms of action and clinical efficacy of BoNT treatment in the prostate. BoNT has demonstrated promising preliminary results for male lower urinary tract symptoms, and translational research suggests novel mechanism of action of BoNT in the prostate. It is important to remember that the application of BoNT in the prostate is not approved by the regulatory agencies and caution should be applied until larger randomized clinical studies are completed.