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Glutathione and lens epithelial function.
Invest Ophthalmol. 1976 May; 15(5):381-93.IO

Abstract

The relationship of the concentration of glutathione (GSH) in lens epithelium to the transport of cations in the lens was studied by decreasing the level of GSH in the epithelium and monitoring subsequent effects in the lens on the distribution of cations, the activity of Na+-K+ ATPase and the uptake and efflux of 86Rb. Oxidation of GSH in cultured rabbit lenses was accomplished by the use of 1 mM tertiary butyl hydroperoxide (TBHP), a reagent which appears to be suitable for the specific oxidation of GSH in this tissue. The concentration of GSH found in the normal lens epithelium was estimated to be 64 mum per gram wet weight or nearly six times that present in the whole lens. A decrease in the concentration of GSH in lens epithelium of 60 per cent or more leads to an increase in hydration, a shift in the distribution of Na+, K+, and Cl-, a decrease in the activity of Na+-K+ ATPase, and a decrease in the active transport, and an increase in the passive diffusion of 86Rb. In the TBHP-treated lenses there is a rapid decrease in the production of lactate, possibly as a result of the inhibition of Na+-K+ ATPase, but the effect on the level of lens ATP is delayed and less pronounced. It appears that the adverse effect on membrane permeability caused by the oxidation of GSH is partially reversed when a high level of GSH returns to the epithelium. However, the decrease in active transport of 86Rb and the inactivation of Na+-K+ ATPase are not reversed by either regeneration of GSH in the tissue or by treatment with exogenous dithiothreitol and may indicate an irreversible conformational change in the enzyme initiated by the loss of the protective effect of GSH. The data indicate that a critical level of GSH is required in the lens epithelium for the maintenance of normal cation transport.

Authors

No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

131114

Citation

Giblin, F J., et al. "Glutathione and Lens Epithelial Function." Investigative Ophthalmology, vol. 15, no. 5, 1976, pp. 381-93.
Giblin FJ, Chakrapani B, Reddy VN. Glutathione and lens epithelial function. Invest Ophthalmol. 1976;15(5):381-93.
Giblin, F. J., Chakrapani, B., & Reddy, V. N. (1976). Glutathione and lens epithelial function. Investigative Ophthalmology, 15(5), 381-93.
Giblin FJ, Chakrapani B, Reddy VN. Glutathione and Lens Epithelial Function. Invest Ophthalmol. 1976;15(5):381-93. PubMed PMID: 131114.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Glutathione and lens epithelial function. AU - Giblin,F J, AU - Chakrapani,B, AU - Reddy,V N, PY - 1976/5/1/pubmed PY - 1976/5/1/medline PY - 1976/5/1/entrez SP - 381 EP - 93 JF - Investigative ophthalmology JO - Invest Ophthalmol VL - 15 IS - 5 N2 - The relationship of the concentration of glutathione (GSH) in lens epithelium to the transport of cations in the lens was studied by decreasing the level of GSH in the epithelium and monitoring subsequent effects in the lens on the distribution of cations, the activity of Na+-K+ ATPase and the uptake and efflux of 86Rb. Oxidation of GSH in cultured rabbit lenses was accomplished by the use of 1 mM tertiary butyl hydroperoxide (TBHP), a reagent which appears to be suitable for the specific oxidation of GSH in this tissue. The concentration of GSH found in the normal lens epithelium was estimated to be 64 mum per gram wet weight or nearly six times that present in the whole lens. A decrease in the concentration of GSH in lens epithelium of 60 per cent or more leads to an increase in hydration, a shift in the distribution of Na+, K+, and Cl-, a decrease in the activity of Na+-K+ ATPase, and a decrease in the active transport, and an increase in the passive diffusion of 86Rb. In the TBHP-treated lenses there is a rapid decrease in the production of lactate, possibly as a result of the inhibition of Na+-K+ ATPase, but the effect on the level of lens ATP is delayed and less pronounced. It appears that the adverse effect on membrane permeability caused by the oxidation of GSH is partially reversed when a high level of GSH returns to the epithelium. However, the decrease in active transport of 86Rb and the inactivation of Na+-K+ ATPase are not reversed by either regeneration of GSH in the tissue or by treatment with exogenous dithiothreitol and may indicate an irreversible conformational change in the enzyme initiated by the loss of the protective effect of GSH. The data indicate that a critical level of GSH is required in the lens epithelium for the maintenance of normal cation transport. SN - 0020-9988 UR - https://www.unboundmedicine.com/medline/citation/131114/Glutathione_and_lens_epithelial_function_ DB - PRIME DP - Unbound Medicine ER -