Modelling the Time Evolution of Active Caspase-3 Protein in the Rat Lens after In Vivo Exposure to Ultraviolet Radiation-B

PURPOSE To introduce a model for the time evolution of active caspase-3 protein expression in albino rat lens up to 24 hours after in vivo exposure to low dose UVR in the 300 nm wavelength region (UVR-300 nm). METHODS Forty Sprague-Dawley rats were unilaterally exposed in vivo to 1 kJ/m2 UVR-300 nm for 15 minutes. At 0.5, 8, 16, and 24 hours after the UVR exposure, the exposed and contralateral not-exposed lenses were removed and processed for immunohistochemistry. The differences in the probability of active caspase-3 expression at four different time points after exposure were used to determine the time evolution of active caspase-3 expression. A logistic model was introduced for the expression of active caspase-3. The parameters for the exposed and the not exposed lenses were estimated for the observation time points. RESULTS The exposure to UVR-300 nm impacted on the parameters of the logistic model. Further, the parameters of the model varied with time after exposure to UVR-300 nm. CONCLUSION The logistic model predicts the impact of exposure to UVR-300 nm on the spatial distribution of probability of active caspase-3 protein expression, depending on time.