Francisco Cruz

GRC-6211, a new oral specific TRPV1 antagonist, decreases bladder overactivity and noxious bladder input in cystitis animal models.

PURPOSE We evaluated the effects of GRC-6211, an orally active TRPV1 antagonist, on the function and noxious input of naïve and inflamed bladders. MATERIALS AND METHODS In urethane (Sigma(R)) anesthetized rats 0.5 ml GRC-6211 (0.001, 0.01, 0.1 and 1 mg/kg weight) or its vehicle (0.5% methylcellulose) were administered through a duodenal catheter and cystometry was done during infusion of saline, 100 microM capsaicin or 0.5% acetic acid (Merck, Feltham, United Kingdom). Cystometry was also performed in WT and TRPV1 knockout mice treated with 1 mg/kg GRC-6211. Cystometry was done in rats inflamed with lipopolysaccharide after receiving 0.1 mg/kg GRC-6221 or vehicle. Spinal c-fos expression induced by 0.5% acetic acid was investigated after 0.1 mg/kg GRC-6211 or vehicle administration. TRPV1 immunoreactivity was evaluated in the bladder after GRC-6211 administration. RESULTS The reflex activity of rat and WT mice naïve bladders was unchanged by GRC-6211 up to a dose of 0.1 mg/kg. At 1 mg/kg contractions were transiently suppressed in naïve rats and WT mice but not in TRPV1 knockout mice. GRC-6211 (0.1 mg/kg) completely prevented capsaicin induced irritation, while the 0.001, 0.01 or 0.1 mg/kg dose decreased the mean +/- SD frequency of bladder contractions during acetic acid infusion from 1.5 +/- 0.3 to 1.35 +/- 0.35 (not significant), 0.9 +/- 0.2 (p <0.05) and 0.8 +/- 0.2 (p <0.05), respectively. Lipopolysaccharide inflamed rats had 1.4 +/- 0.4 and 0.8 +/- 0.1 contractions per minute after vehicle and GRC-6211, respectively (p <0.05). The c-fos expression induced by acetic acid was decreased by GRC-6211 (85.5 +/- 19.1 to 46.7 +/- 9.4, p <0.05). GRC-6211 did not change bladder TRPV1 immunoreactivity. CONCLUSIONS GRC-6211 counteracts the bladder hyperactivity and noxious input induced by cystitis. At high doses it suppresses normal bladder activity by a TRPV1 dependent mechanism. TRPV1 antagonists might be useful for cystitis.

Effect of OnabotulinumtoxinA on Intramural Parasympathetic Ganglia: An Experimental Study in the Guinea Pig Bladder

PURPOSE We investigated whether onabotulinumtoxinA injected in the bladder would affect preganglionic parasympathetic nerve endings in intramural ganglia. MATERIALS AND METHODS Guinea pig bladders were injected with 5 U of botulinum toxin. At 24 hours bladders were collected and processed for immunohistochemistry using tyrosine hydroxylase, and intact and cleaved SNAP-25. To identify the different populations of affected fibers coursing the ganglia we performed double immunoreactions for cleaved SNAP-25 and VAChT, TH or CGRP. RESULTS VAChT immunoreactive fibers were identified in axons and varicosities of presynaptic to postganglionic parasympathetic neurons. Those fibers were also immunoreactive to SV2 and SNAP-25. The rare CGRP and TH immunoreactive fibers coursing in the ganglia did not express SV2 or SNAP-25. After onabotulinumtoxinA injection the cleaved form of SNAP-25 was abundantly expressed in parasympathetic fibers. CONCLUSIONS Botulinum toxin injection in the bladder wall affects preganglionic parasympathetic nerve terminals. This could contribute to the strong effect of botulinum toxin on bladder smooth muscle activity.

Transient receptor potential vanilloid 1 mediates nerve growth factor-induced bladder hyperactivity and noxious input

Whats known on the subject? and What does the study add?

Brain-derived neurotrophic factor, acting at the spinal cord level, participates in bladder hyperactivity and referred pain during chronic bladder inflammation.

Brain-derived neurotrophic factor (BDNF) is a neurotrophin (NT) known to participate in chronic somatic pain. A recent study has indicated that BDNF may participate in chronic cystitis at the peripheral level. However, the principal site of action for this NT is the central nervous system, most notably the spinal cord. The effects of centrally-acting BDNF on bladder function in normal animals and its central role during chronic cystitis are presently unknown. The present study was undertaken to clarify this issue. For that purpose, control non-inflamed animals were intrathecally injected with BDNF, after which bladder function was evaluated. This treatment caused short-lasting bladder hyperactivity; whereas chronic intrathecal administration of BDNF did not elicit this effect. Cutaneous sensitivity was assessed by mechanical allodynia as an internal control of BDNF action. To ascertain the role of BDNF in bladder inflammation, animals with cyclophosphamide-induced cystitis received intrathecal injections of either a general Trk receptor antagonist or a BDNF scavenger. Blockade of Trk receptors or BDNF sequestration notably improved bladder function. In addition, these treatments also reduced referred pain, typically observed in rats with chronic cystitis. Reduction of referred pain was accompanied by a decrease in the spinal levels of extracellular signal-regulated kinase (ERK) phosphorylation, a marker of increased sensory barrage in the lumbosacral spinal cord, and spinal BDNF expression. Results obtained here indicate that BDNF, acting at the spinal cord level, contributes to bladder hyperactivity and referred pain, important hallmarks of chronic cystitis. In addition, these data also support the development of BDNF modulators as putative therapeutic options for the treatment of chronic bladder inflammation.

Co-administration of transient receptor potential vanilloid 4 (TRPV4) and TRPV1 antagonists potentiate the effect of each drug in a rat model of cystitis.

To investigate transient receptor potential vanilloid 4 (TRPV4) expression in bladder afferents and study the effect of TRPV4 and TRPV1 antagonists, alone and in combination, in bladder hyperactivity and pain induced by cystitis.

INTRA-TRIGONAL INJECTION OF BOTULINUM TOXIN A IN PATIENTS WITH BLADDER PAIN SYNDROME - RESULTS AT 9-MONTHS FOLLOW-UP

the number of associated conditions increased (i.e., localized, regional, to systemic), pain, stress, depression, and sleep disturbance increased while social support, sexual functioning and quality of life deteriorated. Anxiety and catastrophizing remained elevated in all groups. Symptom duration was associated with phenotypic progression. CONCLUSIONS: IC/PBS patients have significant biopsychosocial impairment compared to controls. IBS, FM and CFS are more prevalent in IC/PBS patients and result in significant impact. There is progression over time from an organ centric to regional and finally systemic pain syndrome with progression of symptom severity and deterioration of cognitive and psychosocial parameters associated with IC/PBS.

Intravesical Capsaicin and Resiniferatoxin for Bladder Disorders

Abstract Vanilloids, such as capsaicin and resiniferatoxin (RTX), have gained clinical interest, as they modulate urinary bladder primary afferents that control micturition under pathological conditions. In fact, the intravesical use of vanilloid solutions, in particular the intravesical use of RTX solutions, was shown to ameliorate low urinary tract symptoms, such as urinary incontinence and frequency associated with overactive bladder and neurogenic detrusor overactivity. In addition, vanilloids may be useful to treat pain associated with bladder pain syndrome/interstitial cystitis. Nevertheless, the lack of a correct formulation and dosage of intravesical RTX solutions made the results obtained inconsistent and not replicable. However, the rational for the intravesical use of RTX is still strong, which may still justify the undertaking of well-designed clinical studies.

Biomarkers in the Overactive Bladder Syndrome

Overactive bladder (OAB) is a symptomatic complex affecting both men and women. The overall incidence is above 10% but may exceed 40% in the elderly population (Irwin et al., 2006; Irwin et al., 2009; Sexton et al., 2009a). OAB is defined by the International Continence Society (ICS) as a clinical syndrome characterized by urinary urgency, with or without incontinence, usually with frequency and nocturia (Abrams et al., 2002, 2003; Hashim & Abrams, 2007). Urgency, which is a storage symptom defined as a sudden compelling desire to pass urine difficult to defer, is the hallmark symptom as it is the only one that must be present in order to establish the diagnosis of OAB (Abrams et al., 2002, 2003). Several comorbidities are very common among OAB patients, including depression, insomnia and fractures (Coyne et al., 2008; Sexton et al., 2009a; Sexton et al., 2009b). The economic costs of OAB, associated with medical consultations, therapy and diminished productivity at work, may reach billions of dollars (Irwin et al., 2009) and will certainly increase with the demographic shift of an ageing population.

653 INTRATHECAL BLOCKADE OF NGF DECREASES REFERRED PAIN IN RATS MODEL OF CHRONIC BLADDER INFLAMMATION

652 CHEMICAL NEUROMODULATION IN PATIENTS WITH BLADDER PAIN SYNDROME (BPS) R. Pinto *, T. Lopes, C. Cruz, J. Silva, C. Silva, F. Cruz, P. Dinis. Faculty of Medicine of University of Porto, Porto, Portugal; Department of Urology, Hospital de S. João, Porto, Portugal; Institute of Histology and Embryology and IBMC, University of Porto, Porto, Portugal; Department of Urology, Hospital de S. João, Porto, Portugal

654 INTRATHECAL BDNF SEQUESTRATION REDUCES REFERRED PAIN AND BLADDER OVERACTIVITY IN AN ANIMAL MODEL OF CHRONIC BLADDER INFLAMMATION

652 CHEMICAL NEUROMODULATION IN PATIENTS WITH BLADDER PAIN SYNDROME (BPS) R. Pinto *, T. Lopes, C. Cruz, J. Silva, C. Silva, F. Cruz, P. Dinis. Faculty of Medicine of University of Porto, Porto, Portugal; Department of Urology, Hospital de S. João, Porto, Portugal; Institute of Histology and Embryology and IBMC, University of Porto, Porto, Portugal; Department of Urology, Hospital de S. João, Porto, Portugal