Ion pumps and passive cotransport systems are present in the membranes 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 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 limited. 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. It is clear that among many unknown factors, osmotic equilibrium, Na:K ATPase activity and normal GSH levels are necessary to maintain lens transparency. The overall aim of this proposal is to further characterize: mechanisms of ion transport, fluid transport, membrane permeability, metabolic activity and related physiological parameters relevant to the understanding of corneal and lens cell function. To this aim we will use electrophysiological, radiolabelled-tracer and microspectrofluorometric techniques. The latter will exploit recent advances with ion -sensitive intracellular probes to characterize the transport properties of both cultured cells and intact ocular tissue. We expect to provide models of ion and fluid movement across corneal and lens epithelia and the corneal endothelium.
| 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 |
| 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, 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 |
| 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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