Stretch independent regulation of prostaglandin E₂ production within the isolated guinea-pig lamina propria

Nile, C.J. , de Vente, J. and Gillespie, J.I. (2010) Stretch independent regulation of prostaglandin E₂ production within the isolated guinea-pig lamina propria. BJU International, 105(4), pp. 540-548. (doi: 10.1111/j.1464-410X.2009.08705.x)

Abstract

<p>Objective: To use an isolated preparation of the guinea-pig bladder lamina propria (LP) to investigate the effects of adenosine tri-phosphate (ATP) and nitric oxide (NO) on the release of prostaglandin E₂ (PGE₂).</p> <p>Materials and Methods: The bladders of female guinea-pigs (200–400 g) were isolated and opened to expose the urothelial surface. The LP was dissected free of the underlying detrusor muscle and cut into strips from the dome to base. Strips were then incubated in Krebs buffer at 37 °C. Each tissue piece was then exposed to the stable ATP analogue, BzATP, and a NO donor, diethylamine-NONOate (DEANO), and the effect on PGE₂ output into the supernatant determined using the Parameter ^TM PGE₂ enzyme immunoassay kit (R & D Systems, Abingdon, UK). Experiments were repeated in the presence of purinergic receptor and cyclooxygenase (COX) enzymes, COX I and COX II, antagonists. The cellular location of COX I, COX II and neuronal NO synthase (nNOS) within the bladder LP was also determined by immunohistochemistry.</p> <p>Results: PGE₂ production was significantly increased by BzATP. Antagonist studies showed the purinergic stimulation involved both P2X and P2Y receptors. The BzATP response was inhibited by the COX inhibitor indomethacin (COX I >COX II) but not by DUP 697 (COX II >COX I). Thus, BzATP stimulation occurs because of COX I stimulation. NO had no effect on PGE₂ production over the initial 10 min of an exposure. However, PGE₂ output was increased 100 min after exposure to the NO donor. In the presence of NO, the BzATP stimulation was abolished. Immunohistochemistry was used to confirm the location of COX I to the basal and inner intermediate urothelial layers and to cells within the diffuse layer of LP interstitial cells. In addition, nNOS was also located in the basal urothelial layers whilst COX II was found in the interstitial cell layers.</p> <p>Conclusion: There is complex interaction between ATP and NO to modulate PGE₂ release from the bladder LP in the un-stretched preparation. Such interactions suggest a complex interrelationship of signals derived from this region of the bladder wall. The importance of these interactions in relation to the physiology of the LP remains to be determined.</p>

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Nile, Dr Christopher
• Authors: Nile, C.J., de Vente, J., and Gillespie, J.I.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing > Dental School
• Journal Name: BJU International
• ISSN: 1464-4096
• ISSN (Online): 1464-410X
• Published Online: 11 August 2009