advertisement
Abstract #6491 Published in IGR 3-2
Increased human scleral permeability with prostaglandin exposure
Kim JW; Lindsey JD; Wang N; Weinreb RNInvestigative Ophthalmology and Visual Science 2001; 42: 1514-1521
PURPOSE: To investigate the effect of prostaglandins (PGs) on the permeability of human sclera in vitro. METHODS: Twenty-three pairs of human eyebank eyes were studied. Circular pieces of sclera were cultured in low-serum DMFM/F-12 media. Scleral hydration was assessed by measuring wet and dry weight of scleral cultures incubated with medium for three days and with Hanks' buffered saline solution (HBSS) for four hours. To assess scleral permeability, organ-cultured scleral tissues were exposed to 100-500 nM PGF2α, 16-phenyltrinor PGF2α, or PhXA85 (the active form of latanoprost) for one, two, and three days. Scleral permeability was measured using a two-changer Ussing apparatus and rhodamine-dextran polymers dissolved in HBSS (MW = 10,000, 40,000, and 70,000). The movement of each rhodamine-dextran across the cultured sclera was measured using a spectrofluorometer. To understand the biological basis of the permeability change, the media were collected from the treated cultures, and the concentration of MMP-1, 2, and 3 was measured using an enzyme-lined immunosorbent assay. RESULTS: There was no difference in scleral hydration among fresh sclera and sclera incubated with medium for three days, with HBSS for four hours, or with medium for three days followed by HBSS for four hours. Compared to tracer movement across untreated scleral cultures (1.5 x 106 cm/sec for 10 kDa dectran, 0.7 x 106 cm/sec for 40 kDa dextran, and 0.4 x 106 cm/sec for 70 kDa dextran), exposure to PGF2α, 17-phenyltrinor PGF2α, or PhXA85, each increased scleral permeability in a dose- and time-dependent manner. Increases in permeability were greater with the 10 kDa dextran than with the 40 or 70 kDa dectran. The magnitude of these effects was greatest with exposure to PhXA85 and similar with exposure to PGF2α or 17-phenyltrinor-PGF2α. MMP expression was also significantly increased after PG exposure. These increases were generally time- and dose-dependent and greater with MMP-2 and -3 than with MMP-1. CONCLUSIONS: There is increased permeability of human sclera exposed to various PGs in organ culture. This increases permeability is accompanied by increased expression of MMPs.
Dr R.N. Weinreb, Glaucoma Center, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0916, USA. weinreb@eyecenter.ucsd.edu
Classification:
11.4 Prostaglandins (Part of: 11 Medical treatment)
