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Abstract #19152 Published in IGR 3-1
Effects of Rho-associated protein kinase inhibitor Y-27632 on intraocular pressure and outflow facility
Honjo M; Tanihara H; Inatani M; Kido N; Sawamura T; Yue BYJT; Narumiya S; Honda YInvestigative Ophthalmology and Visual Science 2001; 42: 137-144
PURPOSE: To elucidate the roles of Rho-associated protein kinase (ROCK) in regulating intraocular pressure (IOP) and outflow facility in the rabbit eye. METHODS: A specific ROCK inhibitor Y-27632 was used. IOP, outflow facility, and pupil diameter were determined before and after the topical, intracameral, or intravitreal administration of Y-27632, in rabbits. Western blot analysis was used to identify specific ROCK isoform in human trabecular meshwork (TM) cells and bovine ciliary muscle (CM) tissues. The cell morphology and distribution of actin filaments and vinculin TM cells were studied using cell biology techniques. Carbachol (Cch)-induced contraction of isolated bovine CM strips after administration of Y-27632 was measured in a perfusion chamber. Results. In rabbit eyes, administration of Y-27632 resulted in a significant decrease in IOP in a dose-dependent manner. An increase of the outflow facility and pupil size dilation was also observed in Y-27632-treated eyes. Western blot analysis revealed the presence of p160ROCK in human TM cells and bovine CM tissues. In cultured human TM cells, exposure to Y-27632 caused retraction and rounding of cell bodies as well as disruption of actin bundles and impairment of focal adhesion formation. Y-27632 in addition inhibited Cch-induced contraction of isolated bovine CM strips. CONCLUSIONS: Administration of Y-27632 caused a reduction in IOP and an increase in the outflow facility. The in vitro experiments suggest that the IOP-lowering effects of Y-27632 may be related to the altered cellular behavior of TM cells and relaxation of CM contraction. These studies suggest that ROCK inhibitors may have great potential to be developed for treatment of glaucoma and other ocular diseases.
Dr H. Tanihara, Department of Ophthalmology, Tenri Hospital, Mishima-cho 200, Tenri 632-0015, Japan
Classification:
11.14 Investigational drugs; pharmacological experiments (Part of: 11 Medical treatment)
