Normal bladder function is maintained by a coordination of neural input and muscle contraction. However, the extracellular matrix (ECM) of the bladder is also important, both for its contribution to the viscoelastic properties of the bladder and for the normal propagation of muscle contraction through the bladder. The amount of collagen and the ratio of collagen subtypes has been shown to change in aging (skin, heart, liver, lungs), diabetes and other diseases. The hypothesis of the present studies is that similar changes in bladder collagen or other ECM components contribute to the bladder dysfunction associated with aging and disease. The goal of this grant is to document changes in ECM components in normal and dysfunctional bladders (bladder instability) of humans and animals. To accomplish this goal, ECM components (collagen sub-types, elastin, laminin and fibronectin) will be studied using a combination of immunoperoxidase, ELISA and 2-D gel electrophoresis. Bladder function and ECM components will be studied in female rats of different ages and in a model of bladder outlet obstruction with detrusor instability. Control female patients and those with bladder instability will be studied. Detailed bladder function will be studied using video urodynamics, voiding diaries and other measures. Bladder biopsy samples will be taken and ECM characterized as above. The role of the cytokine transforming growth factor-beta (TGF-beta)in bladder ECM synthesis will be studied in vitro using bladder smooth muscle and urothelial cells and in vivo using antagonists of TGF-beta. Bladder dysfunction is a frequent problem, with an annual cost of over $10 billion. Incontinence, which affects approximately 40% of the patients in long-term care facilities and 15% to 30% of the ambulatory population, is a major reason for admission to long- term care facilities. Current therapy for bladder dysfunction is limited; the alternative is often surgery. The studies proposed herein will lead to a better understanding of the changes in bladder ECM which occur in aging and bladder disease. The eventual goal of such studies is to gain insight into the regulation of bladder ECM expression which could be manipulated for therapeutic purposes.
| Kohan, A D; Danziger, M; Vaughan Jr, E D et al. (2000) Effect of aging on bladder function and the response to outlet obstruction in female rats. Urol Res 28:33-7 |
