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.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 21 March 2000 Revised: 12 September 2000 Accepted: 20 September 2000
Rights and permissions
About this article
Cite this article
Dégi, R., Thore, C., Bari, F. et al. Ischemia increases prostaglandin H synthase-2 levels in retina and visual cortex in piglets. Graefe's Arch Clin Exp Ophthalmol 239, 59–65 (2001). https://doi.org/10.1007/PL00007899
Issue Date:
DOI: https://doi.org/10.1007/PL00007899