Arsenite accumulation in the mouse eye

Abstract

Elevated arsenic (As) concentrations in drinking water are a major worldwide public health concern. Exposure to As is associated with carcinogenesis, skin lesions, cardiovascular disease, cognitive deficits, and other disorders. However, little is known regarding chronic As-mediated effects on the eye. Oxidative stress is believed to be an important factor in As-related pathology and is also implicated in certain eye diseases such as cataract. Thus, elevated exposure to arsenic could potentially be a contributing factor for ocular pathology. A pilot study was therefore initiated to determine whether As could be detected in eye tissue of mice exposed to sodium arsenite in drinking water. Total As concentrations were determined by inductively coupled plasma-mass spectroscopy in whole eyes, lens, liver, heart, lung, kidneys, spleen, brain, and hair from mice given 0, 10, 50, or 250 ppm sodium arsenite in their drinking water for 4 wk or 0, 10 or 50 ppm for 6 mo. Dose-dependent increases in As concentration were observed in all organs and tissues. Surprisingly, As concentrations in the eye and lens were significantly higher than those in liver, lung, heart, spleen, and brain and similar to that found in kidneys. The relatively high concentration in the eye, and the lens in particular, suggests As exposure may be a contributing factor in cataract formation in parts of the world where As in drinking water is endemic.

Figure 1

Relative concentrations of inorganic As in tissues from male mice 6 months after continuous exposure to 10 ppm sodium arsenite in drinking water. Elemental analysis was performed as described. The eye lens was dissected from the globe before analysis. * Significant from lens p<0.05.