|Schultz j b,|
Submitted to: Molecular and Cellular Biochemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 9/21/1994
Publication Date: N/A
Citation: Interpretive Summary: The purpose of this study was to test the susceptibility of certain eye lens cells from rabbits and squirrels to ultraviolet light, and to test efficacy of vitamin E in the prevention of light-induced damage to the lens cells. After exposing lens cells to ultraviolet light, those cells that were preserved in a medium containing vitamin E showed less damage as measured by cell survival and biochemical markers for cellular structure and functions compared to non-supplemented lens cells. This finding underscores the potential significance of antioxidant protection and repair mechanisms in the eye lens.
Technical Abstract: The purpose of this study was to observe the near-UV radiation- induced damage to cultured rabbit and squirrel lens epithelial cells as related to destruction and alteration of specific biochemical targets in the cells and to determine the protective effect provided by alpha-tocopherol (a-toc). Confluent monolayers of cultured rabbit and squirrel lens epithelial cells were exposed to black light (BL) lamps, which emit predominantly UV-A radiation. These cells received a mixture 3 J/cm**2 of UV-A and 4 mJ/cm**2 of UV-B per hr. This mixture is termed near UVA (ie: predominantly UV-A). Cells were exposed in Tyrode's or in MEM without or with a-toc added at 2.5 to 10 micrograms/ml. Analysis of cell viability and survival, the physical state of cytoskeletal actin, and the activities of Na-K-ATPase and catalase were determined. Exposure to near UV-A damaged these cells as measured by vital staining and colony forming ability. Pretreatment with a-toc decreased the magnitude of near UV-A cytotoxicity. Near UV-A exposure in MEM always produced more damage to the cells and biochemical targets than in Tyrode's. Cytoskeletal actin was degraded and the activities of Na-K-ATPase and catalase were markedly inhibited by UV exposure. All of these targets were at least partially protected by alpha-tocopherol in the medium. Without a-toc added to the media, the viability and survival of the cells did not recover. Cell viability was better protected from near UV-A by a-toc than was the ability to grow into colonies. This indicates that a-toc protects actin, catalase, and Na-K-ATPase from near UV-A damage.