Treatment of Lower Urinary Tract Symptoms and Overactive Bladder — Focus on Bladder Sensory Innervation

Abstract

Lower urinary tract symptoms (LUTS) are highly prevalent, especially among elderly men and women, with a negative impact on health-related quality of life. LUTS are associated with great emotional costs for individuals and substantial economic costs for society. Recent investigation of LUTS in men noted that bladder dysfunction plays an important role in addition to bladder outlet obstruction. The urothelial release of neurotransmitters such as acetylcholine (ACh), adenosine triphosphate (ATP) and the neuropeptide substance P, and the expression of TRPV1 and P2X3 receptors strongly imply a role for the urothelium in human bladder mechanosensation. An abundance of suburothelial sensory nerves and vesicles containing ACh and ATP in nerve fiber terminals have been found in the human bladder wall, suggesting the lamina propria of the bladder plays an important role in the transmission of a sensation of bladder fullness and in the bladder response to stretch. In addition, nerve growth factor levels have been shown to be elevated in the bladder tissues of men with bladder outlet obstruction, patients with overactive bladders, and women with interstitial cystitis. Based on the results from recent investigations, bladder disorders like neurogenic detrusor overactivity, idiopathic detrusor overactivity, interstitial cystitis, overactive bladder due to bladder outlet obstruction and urothelial dysfunction might have a common pathway in the abnormality of expression of sensory receptors or release of transmitters in the suburothelial nerves or interstitial cells. In this regard, inhibition of receptor expression or transmitter release in the sensory nerve terminals in the suburothelial space might provide good therapeutic effects in the treatment of sensory urgency, interstitial cystitis and detrusor overactivity.