Purpose. To utilize lens organ culture as a system for the screening of potential anti-cataract agents individually and in combination. Methods. Lenses, freshly excised from rats (75-100g) were placed into modified TC-199 culture medium and incubated under standard conditions. The lenses were stressed and opacification induced in vitro by the addition of cataractogenic agents, including H2O2 and high concentrations of sugars, to the medium. The ability of potential therapeutic compounds to protect the lens from these challenges was assessed by histological and gross morphological analyses, as well as measurement of transport parameters, protein leakage and other biochemical parameters. Results. A variety of compounds including antioxidants, calpain inhibitors, phase separation inhibitors and others were tested for efficacy in preventing lens changes. The large majority of these proved to be completely ineffective. One compound, the hydroxylamine of the nitroxide Tempol (Tempol-H) was quite effective at preventing membrane transport damage in lenses exposed to 250 μM H2O2 and was also able to markedly inhibit opacification of lenses exposed to 1.0 mM H2O2. Tempol-H does not react directly with H2O2 and thus its effect is not from decreasing the H2O2 level in the culture medium. Conclusion. Tempol-H may be a useful agent in counteracting oxidative stress in the lens. It is an effective free radical scavenger and readily redox cycles in living cells between the hydroxylamine (Tempol-H) and nitroxide (Tempol) forms.
|Investigative Ophthalmology and Visual Science
|Published - Feb 15 1996
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience