title: M3 muscarinic receptor-like immunoreactivity in sham operated and obstructed guinea pig bladders.
abstract: OBJECTIVE
  Type 3 muscarinic receptors, which are present in the bladder wall, are important for bladder function. However, their role in the context of the urothelium is not well defined. Understanding the role of type 3 muscarinic receptors has been limited by the lack of specific type 3 muscarinic receptor antibodies. Thus, we identified a specific type 3 muscarinic receptor antibody and investigated the site of type 3 muscarinic receptors in sham operated and obstructed guinea pig bladders.
  
  
  METHODS
  The specificity of 4 commercially available type 3 muscarinic receptor antibodies was determined. Immunohistochemistry was then done in bladder tissue from sham operated and obstructed guinea pig bladders.
  
  
  RESULTS
  One of the 4 antibodies examined had the needed specificity in terms of blocking peptide and Western blot characterization. Using this antibody type 3 muscarinic receptor immunoreactivity was associated with muscle cells, nerves and interstitial cells. Four types of interstitial cells were identified, including suburothelial, lamina propria, surface muscle and intramuscular interstitial cells. In the obstructed model the bladder wall was hypertrophied and there was nerve fiber loss. The number of lamina propria, surface muscle and intramuscular interstitial cells was increased but not the number of suburothelial interstitial cells. Also, surface muscle interstitial cells appeared to form clusters or nodes with type 3 muscarinic receptor immunoreactivity.
  
  
  CONCLUSIONS
  Nerve loss and the up-regulation of interstitial cells with type 3 muscarinic receptor immunoreactivity may underlie major functional changes in the pathological bladder. This indicates that type 3 muscarinic receptor specific anticholinergic drugs may affect not only the detrusor muscle, as previously thought, but also interstitial cells and nerve fibers.
authors.affiliation: Department of Urology, University Hospital Maastricht, Maastricht, The Netherlands.
authors.forename: Simone
authors.initials: S
authors.lastname: Grol
authors.forename: Christopher John
authors.initials: CJ
authors.lastname: Nile
authors.forename: Piluca
authors.initials: P
authors.lastname: Martinez-Martinez
authors.forename: Gommert
authors.initials: G
authors.lastname: van Koeveringe
authors.forename: Stefan
authors.initials: S
authors.lastname: de Wachter
authors.forename: Jan
authors.initials: J
authors.lastname: de Vente
authors.forename: James I
authors.initials: JI
authors.lastname: Gillespie
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology*; D015153:Blotting, Western; D002478:Cells, Cultured; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007150:Immunohistochemistry; D008297:Male; D043587:Receptor, Muscarinic M3 / Q000276:immunology* / Q000378:metabolism*; D001743:Urinary Bladder / Q000276:immunology* / Q000378:metabolism* / Q000601:surgery; D001748:Urinary Bladder Neck Obstruction / Q000276:immunology* / Q000378:metabolism* / Q000601:surgery
chemical_list: D000906:Antibodies; D043587:Receptor, Muscarinic M3