EFFECT OF PRENATAL PHENYTOIN EXPOSURE ON THE APICAL ECTODERMAL RIDGES OF CHICK WING BUDS

In the chick embryo, at 96 hours (day 4) of development the apical ectodermal ridge reaches a maximum thickness and height after which it regresses11. [...]in this study, duration of exposure of the drug was 4 days. Studies have shown that phenytoin causes an altered expression of various genes involved in key morphogenetic events13. Since phenytoin can disturb the endogenous metabolic processes, it can also have an adverse effect on the embryological development of the apical ectodermal ridge which may be its primary site of teratogenic action. [...]with this study, in our laboratory settings, the mitotic spindles could be easily identified on the light microscope after staining of the AER sections with Feulgen Nuclear and Light Green stains (fig-1). [...]in our study, this histological feature was used as one of the parameters for assessment of the activity level in the AER. Since the AER is an important signaling center for limb development, it is highly likely that this disturbance of mitotic activity in the AER was responsible for the limb anomalies observed in experimental chicks.