title: The relationship between prostaglandin E receptor 1 and cyclooxygenase I expression in guinea pig bladder interstitial cells: proposition of a signal propagation system.
abstract: OBJECTIVE
  We explored the structural relationship between enzymes producing prostaglandin (cyclooxygenase I) and 1 of the receptor families that respond to prostaglandin (prostaglandin E receptor 1) in the bladder muscle.
  
  
  METHODS
  Nine male guinea pigs were sacrificed by cervical dislocation. Bladders were removed and fixed in 4% paraformaldehyde in phosphate buffered saline. Frozen sections (10 μm) were cut and stained with antibodies to prostaglandin E receptor type 1, cyclooxygenase I and vimentin.
  
  
  RESULTS
  Prostaglandin E receptors 1 was identified on smooth muscle cells, and vimentin positive surface muscle and intramuscular interstitial cells. Muscle staining was less intense than on interstitial cells and had a punctuate appearance. Prostaglandin E receptor 1 expression on interstitial cells was highly localized. Discrete regions of intense staining were noted on interstitial cell processes. Cyclooxygenase I was also expressed in muscle interstitial cells. Cyclooxygenase I positive interstitial cells were more prevalent in the muscle bundles of the inner muscle than in the outer muscle layers. Cyclooxygenase I staining was noted on discrete regions of the cell or cell processes. Double staining with prostaglandin E receptor 1 and cyclooxygenase I suggested that cell regions expressing the former are different from those expressing the latter.
  
  
  CONCLUSIONS
  The discovered arrangement of prostaglandin E receptor 1 and cyclooxygenase I may have the potential to facilitate the propagation of signals in the interstitial cell network. Such a signaling system may have a role in coordinating events, as in bladder pathology, facilitating the global coordinated changes associated with bladder wall remodeling.
authors.affiliation: Department of Urology, Maastricht University Medical Centre, Maastricht, The Netherlands. sajjad_r@yahoo.com
authors.forename: Mohammad Sajjad
authors.initials: MS
authors.lastname: Rahnama'i
authors.forename: Stefan G
authors.initials: SG
authors.lastname: de Wachter
authors.forename: Gommert A
authors.initials: GA
authors.lastname: van Koeveringe
authors.forename: Philip E
authors.initials: PE
authors.lastname: van Kerrebroeck
authors.forename: Jan
authors.initials: J
authors.lastname: de Vente
authors.forename: James I
authors.initials: JI
authors.lastname: Gillespie
mesh_terms: D000818:Animals; D051545:Cyclooxygenase 1 / Q000032:analysis / Q000096:biosynthesis*; D006168:Guinea Pigs; D008297:Male; D058306:Receptors, Prostaglandin E, EP1 Subtype / Q000032:analysis / Q000096:biosynthesis*; D001743:Urinary Bladder / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism*
chemical_list: D058306:Receptors, Prostaglandin E, EP1 Subtype; D051545:Cyclooxygenase 1