Abstract
Purpose: :
To investigate the evolution of active caspase-3 protein expression in albino rat lens after in vivo exposure to low dose UVR-300 nm by immunohistochemistry.
Methods: :
Ten Sprague Dawley rats were unilaterally exposed in vivo to 1 kJ/m2 UVR-300 nm for 15 minutes. At 0.5, 3, 7 and 24 hrs after UVR exposure, both lenses were removed. Three mid-sagittal sections of each lens were analyzed with immunohistochemistry. Active caspase-3 labeling was counted and recorded three times in each section.
Results: :
In general, exposed eyes showed a higher expression of caspase-3 than contralateral non-exposed eyes as indicated by a 95 % confidence interval for the mean difference (CI[0.95] = 13.6 ±0.5). The mean difference of expression of caspase-3 between exposed and contralateral non-exposed lenses was lower in the 0.5 hr group (CI[0.95] =13.1 ±9.0) than in the 3 hrs (CI[0.95] = 14.3 ±5.6) and the 7 hrs (CI[0.95]) = 18.4 ±1.9) groups and then decreased in 24 hour group (CI[0.95] = 8.8 ±7.2). There was no difference in caspase-3 expression between the 0.5 and 24 hrs groups (CI[0.95] = 4.3 ±7.0), but there was a difference in capase-3 expression between the 3 hrs and 7 hrs groups (CI[0.95] = 4.14 ±2.03). There was a difference when comparing the 0.5 and 24 hrs groups versus the 3 and 7 hrs groups (CI[0.95] = 6.21±4.05).
Conclusions: :
UVR exposure increases expression of active caspase-3 in eye lens. There is a peak of expression around 7 hrs after exposure.
Keywords: radiation damage: light/UV • apoptosis/cell death • cataract