The overall goal of the proposed research is to gain further knowledge of the physiology and pharmacology of aqueous outflow in the human eye. A major emphasis in the proposed studies is to characterize the role of cAMP in mediating changes in outflow facility, with an overall hypothesis that there is probably more than one cyclase involved in mediating the responsiveness of the outflow system to such diverse stimuli as epinephrine, prostaglandins, muscarinic agonists and modulators of Na/K/2Cl co-transport.
The specific aims i nclude: (1) identification of isoforms of adenylate cyclase in human outflow tissue and pharmacological characterization of cAMP-mediated outflow in human outflow tissue; (2) pharmacological characterization of the outflow facility increasing-effect of muscarinics which occurs directly on human outflow tissue in vitro and is independent of the ciliary muscle, and mapping of the subtypes of muscarinic receptors in the outflow pathways; and (3) pharmacological characterization and identification of isoforms of the endothelial-like Na/K/2Cl co-transport system which has recently been described in outflow tissue. The proposed studies will make use of physiological, biochemical and molecular biological methods in providing a more complete understanding of the regulation of aqueous outflow in the human eye. Enhanced understanding of the basic mechanisms underlying normal outflow may lend insight into the pathogenesis of primary open angle glaucoma and facilitate development of improved treatments.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY007321-12
Application #
2888313
Study Section
Visual Sciences C Study Section (VISC)
Project Start
1989-04-01
Project End
2001-03-31
Budget Start
1999-04-01
Budget End
2000-03-31
Support Year
12
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Boston University
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
604483045
City
Boston
State
MA
Country
United States
Zip Code
02118
Zhang, X; Wang, N; Schroeder, A et al. (2000) Expression of adenylate cyclase subtypes II and IV in the human outflow pathway. Invest Ophthalmol Vis Sci 41:998-1005
Erickson, K A; Schroeder, A (2000) Direct effects of muscarinic agents on the outflow pathways in human eyes. Invest Ophthalmol Vis Sci 41:1743-8
Siegner, S W; Netland, P A; Schroeder, A et al. (2000) Effect of calcium channel blockers alone and in combination with antiglaucoma medications on intraocular pressure in the primate eye. J Glaucoma 9:334-9
Zhang, X; Schroeder, A; Erickson, K A (1999) Effect of continuous administration of a cholinergic agonist on [3H]4-DAMP binding and m3 mRNA expression in cultured human ciliary muscle cells. J Ocul Pharmacol Ther 15:153-63
Al-Aswad, L A; Gong, H; Lee, D et al. (1999) Effects of Na-K-2Cl cotransport regulators on outflow facility in calf and human eyes in vitro. Invest Ophthalmol Vis Sci 40:1695-701
Zhang, X; Hernandez, M R; Yang, H et al. (1995) Expression of muscarinic receptor subtype mRNA in the human ciliary muscle. Invest Ophthalmol Vis Sci 36:1645-57
Erickson, K A; Schroeder, A; Netland, P A (1995) Verapamil increases outflow facility in the human eye. Exp Eye Res 61:565-7
Schuman, J S; Erickson, K; Nathanson, J A (1994) Nitrovasodilator effects on intraocular pressure and outflow facility in monkeys. Exp Eye Res 58:99-105
Erickson, K; Liang, L; Shum, P et al. (1994) Adrenergic regulation of aqueous outflow. J Ocul Pharmacol 10:241-52
Liang, L L; Epstein, D L; de Kater, A W et al. (1992) Ethacrynic acid increases facility of outflow in the human eye in vitro. Arch Ophthalmol 110:106-9

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