Attenuation of Bladder Overactivity in Kit (ws /ws) Mutant Rats

Hypothesis / aims of study The interstitial cells of Cajal (ICC) are primary pacemaker cells responsible for generating smooth muscle activity in the gastrointestinal tract. ICCs express the proto-oncogene c-kit, 3 and signaling via the receptor kinase gene product, KIT, is essential for the development of phenotype and rhythmicity. ICC-like cells form close connections with suburothelial nerves by gap junctions, supposedly involved in signaling pathways of the bladder, and may play a role in moderating the sensory process and lead to initiation of the micturition reflex. Although KIT is used as an identification marker of ICCs and ICC-like cells, recent reports have suggested that KIT is not only a detection marker of these cells, but also may play a crucial role in the control of bladder function. In the present study, to clarify whether disturbance of the KIT pathways affects bladder activity, we examined morphological and physiological findings in the bladder of KIT mutant rats to identify the role of KIT in the control of bladder function, and discussed the potential role of KIT-positive ICC-like cells in the urinary bladder.