The broad, long term aims of this program are to describe the mechanisms of osmoregulation in the cell membranes of ocular epithelia and their possible derangement in ocular disease. In this period of support, membrane vesicles from the len's fibers and epithelium are used to detect mechanisms such as the Na+/H+ and Ca++/Na+ exchangers, the 2Cl-Na+K+ co-transporter and the Na+K+ ATPase. The activating effects of oxidative agents are tested on these membrane transport processes as well as the protection of natural antioxidating agents. Fluorescent probes SBFI for Na+, SNARF- l for H+, Fura 2 for Ca++ and SPQ for Cl- are used. The membrane mechanisms of ocular trabecular meshwork (TBM) cells in tissue culture will bc studied from the point of view of osmoregulation and contractile properties, utilizing imaging and quantitative microscopy. Adrenergic, cholinergic steroidal and oxidative agents will be tested on these TBM cell properties. Membrane events of human corneal epithelial cells (HCE) in tissue culture will be examined. Cell volume regulation and junction formation will be studied in the HCE transformed cell line utilizing imaging, quantitative microscopy and fluorescent probes. The work for this period will be of importance to the understanding of the formation of cataracts, the basic mechanisms of control of intraocular pressure and the cell biology of the corneal epithelium in health and disease.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY001340-23
Application #
2391639
Study Section
Visual Sciences A Study Section (VISA)
Project Start
1977-12-01
Project End
1999-03-31
Budget Start
1997-04-01
Budget End
1999-03-31
Support Year
23
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Miami Rosenteil School
Department
Type
DUNS #
625174149
City
Miami
State
FL
Country
United States
Zip Code
33149
Hoffmann, E K; Hoffmann, E; Lang, F et al. (2002) Control of Cl- transport in the operculum epithelium of Fundulus heteroclitus: long- and short-term salinity adaptation. Biochim Biophys Acta 1566:129-39
Zadunaisky, J A (1996) Chloride cells and osmoregulation. Kidney Int 49:1563-7
Zadunaisky, J A; Cardona, S; Au, L et al. (1995) Chloride transport activation by plasma osmolarity during rapid adaptation to high salinity of Fundulus heteroclitus. J Membr Biol 143:207-17
Fijisawa, K; Ye, J; Zadunaisky, J A (1993) A Na+/Ca2+ exchange mechanism in apical membrane vesicles of the retinal pigment epithelium. Curr Eye Res 12:261-70
Scheide, J I (1993) A diel rhythm of the short-circuit current expressed by the opercular epithelium of the killifish, Fundulus heteroclitus. J Exp Zool 265:88-91
Ye, J J; Zadunaisky, J A (1992) Ca2+/Na+ exchanger and Na+,K+ 2Cl- cotransporter in lens fiber plasma membrane vesicles. Exp Eye Res 55:797-804
Ye, J; Zadunaisky, J A (1992) Study of the Ca2+/Na+ exchange mechanism in vesicles isolated from apical membranes of lens epithelium of spiny dogfish (Squalus acanthias) and bovine eye. Exp Eye Res 55:243-50
Ye, J J; Zadunaisky, J A (1992) A Na+/H+ exchanger and its relation to oxidative effects in plasma membrane vesicles from lens fibers. Exp Eye Res 55:251-60
Ye, J J; Frenkel, K; Zadunaisky, J A (1992) Lens opacification and H2O2 elevation induced by a tumor promoter. Lens Eye Toxic Res 9:37-48
Pearce, S F; Zadunaisky, J A (1991) Characterization of BADS-binding proteins in epithelial plasma membranes. J Membr Biol 123:235-45

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