Novel intervention strategies for neurogenic bladder

University Of Pittsburgh At Pittsburgh, Pittsburgh PA

Investigators

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Abstract

Description (provided by applicant): It is proposed to critically evaluate several promising neuro-urological treatment options for the neurogenic bladder. The first priority will be to study the effects of intravesical instillation of vanilloid receptor agonists, which cause functional C-fiber afferent lesion, in both the clinical setting and in rat models. An additional priority of Project 4 is to determine if RTX treatment during the spinal shock phase can prevent the severe complications of detrusor hyperreflexia, autonomic dysreflexia, and detrusor-sphincter dyssynergia from developing. The project will undertake the first ever study to evaluate urologic neuroprotective therapy based on logical rational and promising preliminary data. The potential clinical benefits for SCI patients may be enormous. Aim 1 of Project 4 proposes to identify and characterize the long-term clinical outcome and to establish the safety of repeated intravesical RTX therapy in traumatic SCI and MS patients with detrusor hyperreflexia. Aim 2 proposes to systematically study the effect of three vanilloids in an SCI rat model, including comparison of effective doses for functional and anatomical C-fiber lesion (Aim 2-a), the effect of short- versus long-term (repeated) intravesical administration at different doses (Aim 2-b), therapeutic versus prophylactic intravesical administration (Aim 2-c), and alternative non-toxic vehicles for instillation (Aim 2-d). Metabolic cage studies will be utilized to determine micturition frequency in awake animals and the effect on detrusor hyperreflexia, autonomic dysreflexia and detrusor-sphincter dyssynergia will be determined using a variety of physiological techniques. Aim 3 proposes to evaluate alternative treatment strategies, such as the use of intramural bladder injection of botulinum toxin (BoTox) for detrusor hyperreflexia (Aim 3-a), the use of pelvic floor injection of BoTox and Conopeptide Ml for long-and short-term treatment of detrusor-sphincter dyssynergia using the rat SCI model (Aim 3-b), and the use of gene therapy to treat detrusor hyperreflexia, autonomic dysreflexia, and detrusor-sphincter dyssynergia in SCI rats and to develop a spinal cord intact model to study C-fiber hyperexcitability and detrusor hyperreflexia in the absence of detrusor-sphincter dyssynergia (Aim 3-c). Herpes simplex virus (HSV) transfected with nerve growth factor (NGF) and preproenkephalin (PPE) will be tested (HSV-NGF and HSV-PPE, respectively). Bladders and urine from the rat studies will be harvested for gross and immuno-histological examination, determination of tissue structure-function relationships (Project 2) and presence or absence of cancer markers (Project 3). Comparisons to the results of vanilloid experiments in the acute SCI cat model (Project 1) will also be made. This Project builds on the commitment of the participants to SCI research, and the synergistic and collaborative history of the laboratories.