Prostaglandin receptor EP1 and EP2 site in guinea pig bladder urothelium and lamina propria.
OBJECTIVE
Urothelium has 2 main functions. It is a barrier to urine and has a sensory role. In response to stretch urothelium releases various substances that modulate afferent nerve activity. Recent data on the localization of cyclooxygenase type 1, the enzyme responsible for prostaglandin production, suggests that prostaglandin may have complex local action.


METHODS
The bladders of 7 guinea pigs were stained for prostaglandin receptors type 1 and 2, and costained for vimentin and cyclooxygenase I.


RESULTS
Prostaglandin receptor type 1 staining was seen in urothelial cells and in the suburothelium. Urothelial staining, which was often punctuate and weak, was detected in all urothelial cell layers, including suburothelial cells. In contrast, strong prostaglandin receptor type 2 staining was seen in the urothelium and in suburothelial cells. Cyclooxygenase I was absent in interstitial cells and umbrella cells with the highest concentration in the basal cell layer.


CONCLUSIONS
Interstitial cells express prostaglandin receptor types 1 and 2, indicating that they can respond to prostaglandin. Umbrella cells do not express cyclooxygenase I. Cyclooxygenase I was present in basal urothelial cells, making them a possible site of prostaglandin synthesis. Thus, prostaglandin produced by urothelium may target prostaglandin receptor types 1 and 2 in the urothelium and suburothelium. Therefore prostaglandin is hypothesized to have a role in signal regulation in the bladder wall.
Rahnama'i
Mohammad Sajjad
MS
Department of Urology, Maastricht University Medical Centre, Maastricht, The Netherlands. sajjad_r@yahoo.com
van Koeveringe
Gommert A
GA
Essers
Paul B
PB
de Wachter
Stefan G G
SG
de Vente
Jan
J
van Kerrebroeck
Philip E
PE
Gillespie
James I
JI
D000818:Animals; D006168:Guinea Pigs; D008297:Male; D009092:Mucous Membrane / Q000737:chemistry; D018078:Receptors, Prostaglandin E / Q000032:analysis*; D058306:Receptors, Prostaglandin E, EP1 Subtype; D058307:Receptors, Prostaglandin E, EP2 Subtype; D001743:Urinary Bladder / Q000737:chemistry*; D019459:Urothelium / Q000737:chemistry
D018078:Receptors, Prostaglandin E; D058306:Receptors, Prostaglandin E, EP1 Subtype; D058307:Receptors, Prostaglandin E, EP2 Subtype