The role of the human bladder lamina propria myofibroblast
Version of Record online: 7 JAN 2003
Volume 91, Issue 1, pages 89–93, January 2003
How to Cite
Wiseman, O.J., Fowler, C.J. and Landon, D.N. (2003), The role of the human bladder lamina propria myofibroblast. BJU International, 91: 89–93. doi: 10.1046/j.1464-410X.2003.03802.x
- Issue online: 7 JAN 2003
- Version of Record online: 7 JAN 2003
- Accepted for publication 18 September 2002
- bladder ultrastructure;
To describe the ultrastructure and relationship to nerves of the myofibroblast in the human bladder lamina propria, and discuss its possible role in bladder function, including sensing stretch, as the response of the bladder to stretch has been thoroughly investigated by afferent nerve recordings, but specialized stretch sensing organs have yet to be identified.
MATERIALS AND METHODS
Flexible cystoscopic bladder biopsies were obtained from patients with detrusor hyper-reflexia and from controls. Systematic electron micrographs were obtained throughout the lamina propria, and the presence and location of cells with ultrastructural characteristics of myofibroblasts noted, together with their relation to surrounding nerves.
Within the lamina propria there was a layer of cells with the cytological characteristics of both fibroblasts and smooth muscle cells, that included bundles of fine cytoplasmic filaments, dense bodies, linear arrays of subsurface vacuoles, and the presence of an interrupted basal lamina. This combination of features is characteristic of the myofibroblast. These cells had close contacts with unmyelinated axonal varicosities containing a mixture of clear and large dense-cored vesicles, or clear vesicles alone.
There is a layer of cells with the ultrastructural characteristics of myofibroblasts within the human bladder lamina propria. Their close contacts with nerves containing both small clear, and small clear with dense-cored, vesicles implies they have both an efferent and an afferent nerve supply, possibly functioning as a bladder stretch receptor. Furthermore, because of their similarities with the interstitial cells of Cajal in the gut, which are claimed to modulate small intestinal function, we discuss other possible roles for bladder lamina propria myofibroblasts.