Biochim Biophys Acta. 2004 Jan 5; 1670(1): 12-18.  Related Articles, Links  

 
Protective effect of ascorbate against oxidative stress in the mouse lens.

Hegde KR, Varma SD.

Departments of Biochemistry and Ophthalmology, University of Maryland School of
Medicine, 10 South Pine Street, MSTF 500-A, 21201, Baltimore, MD, USA

The purpose of this study was to determine if high ascorbate of the human
aqueous protects the lens against oxidative stress. Previous studies with the
rat lens have been inconclusive because of its fortification with aldose
reductase (AR), an important antioxidant. The human lens is deficient in this
activity. These studies were hence done with the mouse lens, a species
deficient in this enzyme. The reactive oxygen species (ROS)-induced
physiological damage to the tissue was assessed in organ culture, by measuring
its ability to actively transport 86Rb(+) ions, in the absence and presence of
ascorbate. In addition, the status of tissue metabolism and its antioxidant
reserve were assessed by quantitating ATP and glutathione (GSH). As expected,
ROS decreased the membrane transport activity as well as the levels of ATP and
GSH. Ascorbate minimized these toxic effects substantially. The presence of
high ascorbate, therefore, appears highly beneficial in protecting the lens
against oxidative damage and cataract formation, despite a deficiency of AR.
The findings therefore appear to be significant from the point of view of using
this nutrient for delaying the onset of cataract development in human beings,
therapeutically as well as nutritionally.

PMID: 14729137 [PubMed - as supplied by publisher]

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