Advertisement

Ischemia increases prostaglandin H synthase-2 levels in retina and visual cortex in piglets

  • Rózsa Dégi
  • Clara Thore
  • Ferenc Bari
  • Nishadi Thrikawala
  • Antal Nógrádi
  • Robins. Greg
  • Ferenc Domoki
  • Tracy C. Beasley
  • D. W. Busija
Laboratory Investigation

Abstract 

Background: Ischemia increases levels of prostaglandin H synthase-2 (PGHS-2) in neonatal brain and cerebral vasculature, but effects on the developing visual system are unknown. We examined the effects of ischemia on PGHS-2 mRNA and protein levels in the retina and visual cortex in anesthetized piglets. Methods: Ten minutes of complete retinal and brain ischemia was induced by increasing intracranial pressure. After 2–12 h of reperfusion, samples of retina and visual cortex were collected for determinations of levels of PGHS-2 mRNA (RNase protection assay) or protein (immunohistochemistry and western blotting). Tissues also were obtained from control animals. Results: Levels of PGHS-2 mRNA were undetectable in control animals but showed a dramatic increase at 2–4 h in the cortex and retina in animals exposed to ischemia. Detectable but limited PGHS-2 immunoreactivity (IR) was present in the retina and visual cortex from control animals. In piglets not subjected to ischemia, PGHS-2 IR was localized mainly to the outer limiting membrane and to the Müller cells. Ischemia induced a marked increase in PGHS-2 IR in the neural retina, with the greatest increase in the photoreceptor layer. PGHS-2 levels in whole retina also increased at 8 h after ischemia. In the intact visual cortex PGHS-2 IR was evident in layers II and V. Ischemia increased the intensity of IR in layers II/III as well as layer V. Conclusions: Detectable amounts of PGHS-2 protein are present in the piglet retina and visual cortex under normal conditions, but levels are markedly increased 8–12 h after ischemic stress. Enhanced PGHS-2 levels after ischemic stress may contribute to delayed pathological changes of the visual system in the neonate.

Keywords

Ischemia Retina Prostaglandin Control Animal Visual System 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

Copyright information

© Springer-Verlag Berlin Heidelberg 2001

Authors and Affiliations

  • Rózsa Dégi
    • 1
  • Clara Thore
    • 1
  • Ferenc Bari
    • 1
  • Nishadi Thrikawala
    • 1
  • Antal Nógrádi
    • 2
  • Robins. Greg
    • 1
  • Ferenc Domoki
    • 1
  • Tracy C. Beasley
    • 1
  • D. W. Busija
    • 1
  1. 1.Department of Physiology and Pharmacology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157-1083, USA e-mail: dbusija@wfubmc.edu Tel.: +1-336-7164355 Fax: +1-336-7160237US
  2. 2.Department of Ophthalmology, Albert Szent-Györgyi Medical University, Szeged, HungaryHU

Personalised recommendations