Investigative ophthalmology & visual science
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Invest. Ophthalmol. Vis. Sci. · Sep 1997
Alkali burn-induced synthesis of inflammatory eicosanoids in rabbit corneal epithelium.
Alkali burning of the rabbit cornea is a well-established model for the study of anterior surface inflammation, neovascularization, and wound-healing processes. 12-hydroxyeicosanoids have been implicated as mediators of such responses. 12(S)-hydroxyeicosatetraenoic acid (12[S]-HETE) is a lipoxygenase-derived arachidonate metabolite and 12(R)-hydroxyeicosatetraenoic acid (12[R]-HETE) is formed by a cytochrome P450 monooxygenase; both give rise to the potent angiogenic factor 12(R)-hydroxyeicosatrienoic acid (12[R]-HETrE). In this study, the authors correlate the pattern of their synthesis in the corneal epithelium with the inflammatory response after alkali injury. ⋯ The results demonstrate that surviving and regenerating epithelium has an increased capacity of synthesizing 12(S)-HETE and 12(R)-HETE and that maximal production of 12(R)-HETrE, a known direct and indirect angiogenic factor, coincides with neovascularization in this model. Thus, the lipoxygenase and cytochrome P450-dependent activities increased in a time-dependent manner, indicating the potential involvement of both pathways in the inflammatory response to alkali burn. The formation of significant quantities of 12(R)-HETE and 12(R)-HETrE is a novel finding in this alkali injury model.
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Invest. Ophthalmol. Vis. Sci. · Aug 1997
Proteoglycans in the human sclera. Evidence for the presence of aggrecan.
The proteoglycans synthesized and accumulated within the adult human sclera (aged 50 to 80 years) were identified by their size, glycosaminoglycan side chains, and core proteins in an effort to characterize the proteoglycan content of the human sclera. ⋯ The adult human sclera contains three major proteoglycans; aggrecan, biglycan, and decorin. It is likely that these proteoglycans contribute to the structural properties of the sclera and that the ratios of these proteoglycans will change with age, specific region, and condition of the sclera.
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Invest. Ophthalmol. Vis. Sci. · Jun 1997
Prophylactic and therapeutic efficacy of immunoglobulin G antibodies to Pseudomonas aeruginosa lipopolysaccharide against murine experimental corneal infection.
To evaluate the efficacy of lipopolysaccharide (LPS)-specific antibodies administered prophylactically or therapeutically to protect against corneal challenge with Pseudomonas aeruginosa. ⋯ In an experimental model of P. aeruginosa keratitis, systematically delivered IgG antibodies directed against the O-side-chain antigens of P. aeruginosa, LPS conferred protection against severe corneal damage when administered both prophylactically and therapeutically.
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Invest. Ophthalmol. Vis. Sci. · Oct 1996
Adenosine mediates hypoxic induction of vascular endothelial growth factor in retinal pericytes and endothelial cells.
To determine the mechanistic role for adenosine and adenosine receptors in the hypoxic induction of vascular endothelial growth factor (VEGF) in retinal microvascular cells. ⋯ These data suggest that the hypoxia-induced accumulation of adenosine stimulates VEGF gene expression through stimulation of adenosine A2a receptor and subsequent activation of the cAMP-dependent protein kinase A pathway in retinal vascular cells.
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Invest. Ophthalmol. Vis. Sci. · Sep 1996
The involvement of polyamines in the proliferation of cultured retinal pigment epithelial cells.
To investigate the involvement of polyamines (putrescine, spermidine, and spermine) in the proliferation of retinal pigment epithelium (RPE) using cultured bovine RPE cells. ⋯ Polyamines are essential for the proliferation of cultured bovine RPE cells. These data suggest that, of the polyamines, spermine has the greatest effect on DNA synthesis although other polyamines can substitute for spermine at higher concentrations with similar results. As for polyamine metabolism in RPE proliferation, it is possible that SAMDC is the key enzyme rather than ODC.