Constitutive expression and localization of COX-1 and COX-2 in rabbit irisand ciliary body

Citation
J. Damm et al., Constitutive expression and localization of COX-1 and COX-2 in rabbit irisand ciliary body, EXP EYE RES, 72(6), 2001, pp. 611-621
Citations number
34
Language
INGLESE
art.tipo
Article
Categorie Soggetti
da verificare
Journal title
EXPERIMENTAL EYE RESEARCH
ISSN journal
0014-4835 → ACNP
Volume
72
Issue
6
Year of publication
2001
Pages
611 - 621
Database
ISI
SICI code
0014-4835(200106)72:6<611:CEALOC>2.0.ZU;2-S
Abstract
Prostaglandins are involved in the regulation of intraocular pressure and t he blood-aqueous barrier of the eye, and are used for the treatment of glau coma. The decrease of the constitutively expressed PG-synthesizing enzyme c yclooxygenase-2 (COX-2) has been demonstrated in the ciliary non-pigmented epithelial layer of patients with primary open angle glaucoma. Little is kn own about the distribution of COX-1 and COX-2 in animals. We investigated t his in the iris and ciliary body of the normal rabbit eye. The presence of COX-1 and COX-2 in freshly excised iris and ciliary body tissue from adult New Zealand White albino rabbits was demonstrated by real-time RT-PCR, and Western blot analysis. The localization of both isoforms and of the neuron- specific protein gene product 9.5 was determined by indirect immunofluoresc ence. Both enzymes are expressed in the iris and the ciliary body. Immunofl uorescence studies including double staining techniques localized COX-1 and COX-2 to about 50% of cells in the stromal tissue of iris and ciliary body , mainly on the corneal side. They were co-localized in about 75 % of these cells. Whereas all stained cells were positive for COX-1, COX-2 showed a g radient-like distribution in the stroma, with some restriction of expressio n near the epithelial layers, which we clearly showed to be completely nega tive for both COX-1 and COX-2. Also, neuronal elements did not show COX-1 o r COX-2 immunoreactivity. These results establish the presence of COX-1 and COX-2 on the RNA and protein levels in normal, unstimulated rabbit iris an d ciliary body. The pattern of distribution suggests a role for both enzyme s in maintaining the physiology of the eye. In contrast to our results in m an, non-pigmented epithelial cells of the ciliary body did not express immu noreactivity. This could account for differences in the regulation of intra ocular pressure and/or blood-aqueous barrier between human and rabbit eyes. (C) 2001 Academic Press.