Ion pumps and passive cotransport systems are present in the membrane of practically all animal cells, to maintain cellular ionic composition, to transport electrolytes and fluid across epithelia, and to maintain an osmotic balance and regulate volume of the cells. Furthermore, ion pumps in cell membranes of the cornea and lens have a crucial role in maintaining the transparency of these tissues. The anatomical and functional integrity of the endothelium is critical for maintaining the transparency of the cornea. However, medical management of cell loss and physiological function is liimited. Thus, research to develop methods to enhance fluid transport is highly relevant. Cataract is a prevalent health problem for which there is no medical treatment. Many mechanisms contribute to the maintenance of lens transparency. In recent years it has become clear that among many unknown factors, osmotic equilibrium, Na:K ATPase activity and normal GSH levels are necessary to maintain lens transparency.
The aim i s to further characterize: mechanisms of ion transport, fluid transport, membrane permeability, transport ATPases, metabolic activity and related physiological parameters important for the maintenance of the transparency of the cornea and lens. To this aim, we will use electrophysiological, biochemical and spectrofluorometric techniques. Data will be analyzed using conventional electrical modelling as well as the formalism of irreversible thermodynamics. We expect to provide models of ion and fluid movement across the corneal epithelium, corneal endothelium and lens membranes.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY000160-17
Application #
3255147
Study Section
Physiology Study Section (PHY)
Project Start
1976-12-01
Project End
1990-11-30
Budget Start
1986-12-01
Budget End
1987-11-30
Support Year
17
Fiscal Year
1987
Total Cost
Indirect Cost
Name
Mount Sinai School of Medicine
Department
Type
Schools of Medicine
DUNS #
City
New York
State
NY
Country
United States
Zip Code
10029
Candia, Oscar A; Gerometta, Rosana M; Danias, John (2014) Tissue plasminogen activator reduces the elevated intraocular pressure induced by prednisolone in sheep. Exp Eye Res 128:114-6
Alvarez, Lawrence J; Zamudio, Aldo C; Candia, Oscar A (2013) Sildenafil stimulates aqueous humor turnover in rabbits. Exp Eye Res 111:67-70
Gerometta, Rosana; Kumar, Sandeep; Shah, Shaily et al. (2013) Reduction of steroid-induced intraocular pressure elevation in sheep by tissue plasminogen activator. Invest Ophthalmol Vis Sci 54:7903-9
Wallace, Julian M; Chiu, Michael K; Nandy, Anirvan S et al. (2013) Crowding during restricted and free viewing. Vision Res 84:50-9
Gerometta, Rosana; Alvarez, Lawrence J; Candia, Oscar A (2012) Sildenafil accelerates anterior chamber refilling after paracentesis in sheep and rabbits. Invest Ophthalmol Vis Sci 53:565-73
Candia, Oscar A (2011) Surface and volume changes in the lens during accommodation. Invest Ophthalmol Vis Sci 52:3698
Gerometta, Rosana; Escobar, D; Candia, Oscar A (2011) An hypothesis on pressure transmission from anterior chamber to optic nerve. Med Hypotheses 77:827-31
Gerometta, Rosana; Alvarez, Lawrence J; Candia, Oscar A (2011) Effect of sildenafil citrate on intraocular pressure and blood pressure in human volunteers. Exp Eye Res 93:103-7
Zamudio, Aldo C; Candia, Oscar A (2011) Interaction between mechanical and osmotic forces in the isolated rabbit lens. Exp Eye Res 93:798-803
Candia, O A; Zamudio, A C; Alvarez, L J (2010) Mechanical stretching forces oppose osmotic lens swelling. Exp Eye Res 91:472-4

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