Mechanisms of Disease: involvement of the urothelium in bladder dysfunction

Abstract

SUMMARYAlthough the urinary bladder urothelium has classically been thought of as a passive barrier to ions and solutes, a number of novel properties have been recently attributed to urothelial cells. Studies have revealed that the urothelium is involved in sensory mechanisms (i.e. the ability to express a number of sensor molecules or respond to thermal, mechanical and chemical stimuli) and can release chemical mediators. Localization of afferent nerves next to the urothelium suggests that urothelial cells could be targets for neurotransmitters released from bladder nerves or that chemicals released by urothelial cells could alter afferent nerve excitability. Taken together, these and other findings highlighted in this article suggest a sensory function for the urothelium. Elucidation of mechanisms that influence urothelial function might provide insights into the pathology of bladder dysfunction.

A possible role of the cholinergic and purinergic receptor interaction in the regulation of the rat urinary bladder function

“…However, expression of several isoforms of the nicotinic receptor has been demonstrated in vascular smooth muscle (Brüggmann et al, 2002). Nicotinic receptors are also found in the urothelium in urinary bladder (Beckel et al 2006;Birder and de Groat, 2007). Our study provides evidence that while nicotinic receptors are present on the bladder smooth muscle cells, too, their activation is indeed not accompanied by an elevation in intracellular Ca 2+ concentration.…”

Spinal cord injury sequelae alter drug pharmacokinetics: an overview

“…Following SCI, the bladder is afflicted by detrusor hyperreflexia and increased activity of the urethral sphincter. 20 Integumentary. Autonomic dysfunction on a systemic scale disrupts homeostatic blood flow and may lead to defective microvascular circulation of the skin.…”

The physiological function of lower urinary tract smooth muscle

“…The body of the bladder -the dome -consists of smooth muscle bounded on the inner face by a urothelium/suburothelium and on the outer face by serosa (Figure 2). Although beyond the scope of this review, the urothelium/suburothelium does more than separate the detrusor muscle from the urine in the bladder lumen, it is the site of afferent sensation and also can exert a direct influence on detrusor function itself (see below) -(reviewed in Birder and de Groat, 2007;Hanna-Mitchell and Birder, 2008). Detrusor muscle cells are spindle-shaped single nucleated cells organized into bundles separated by connective tissue.…”