[Retinoic acid--a teratogenic factor in caudal dysgenesis. Experimental models and hypothesis for pathogenesis].

Using teratogen--trans-retinoic acid (Sigma Chemical)--caudal malformations are experimentally induced in mice of the Spriche-Dolly breed. For the purpose the aforementioned reagent is injected into pregnant mice at 6-hour intervals dose 29 mg/kg. In stages between two and four paired somites, supravital staining with Nile blue sulfite (in 1:50,000 Ringer solution at 37 degrees C for 30 min) is done, followed by histological assessment of tissue sections. The malformation noted are summed up in an attempt to draw conclusions about their presumable pathogenesis.