[Study of apoptosis and mitosis mechanisms in the eye. Experimental model of gestational toxic syndrome].

OBJECTIVE

To improve knowledge of the mechanisms of cellular differentiation and proliferation during retinal development, by studying cellular and molecular damage in a rat model of prenatal ethanol exposure.

METHODS

Female, juvenile Wistar rats (200g body weight) and their offspring were divided into two groups, which were fed a liquid diet: 1) ethanol-exposed group (5% ethanol weight/vol as 35% of daily total calories) and 2) isocaloric control group (maltose/dextrin as 35% of daily total calories). Eyeballs were obtained at 21 days of gestation, embedded in paraffin, and immunodetection procedures performed on apoptotic (TUNEL) and mitotic profiles, which were observed and photographed using a confocal microscope.

RESULTS

Analysis of the microphotographs revealed a statistically significant increase of apoptotic profiles and a decrease in mitotic profiles in the ethanol exposed group compared to controls (p<0.05). Ganglion cells and photoreceptors showed more changes than other retinal cell phenotypes. These findings suggest that abnormalities in the differentiation and proliferation processes of the retina were caused by the alcohol exposure.

CONCLUSIONS

Alcohol abuse during pregnancy alters development of the visual system by inducing developmental changes in the mitotic and apoptotic processes of the retina. These latter changes may be the result of changes in the expression of regulatory genes as well as the result of alteration in signalling pathways for both differentiation-proliferation and apoptotic events.