Effect of All-Trans Retinoic Acid on Epithelialization of Blastema Tissue in vitro

Retinoic acid has a major role in a variety of biological processes including growth and differentiation. One of these effects is epithelialization seen in blastema tissue exposed to different concentration of retinoic acid، due to its embryo-like cells. The main objective of this research was to investigate an experimental studies of employed different concentration of retinoic acid on embryonic- like tissue as an experimental model in vitro. This research is interventional study. The blastema tissue was prepared as the rings by punching pinna of New Zealand white rabbits with professional ethics. Then blastema tissues were cultured with different dose of retinoic acid (10-5 µl/ml، 10-4 µl/ml، 10-3 µl/ml) and evaluated in days of 3، 7، 14، 21 and 28 by histotechniques such as hematoxylin and eosin and Masson''s trichrome staining. The results showed that epithelialization process occurs at the day of 14 in control specimen (without retinoic acid) but samples treated with RA in concentration of 10-5 µl/ml show increases in epithelialization. Cell death was seen with concentration of 10-3 µl/ml. Results revealed that retinoic acid has an effect on epithelialization of dynamic tissues such as blastema which has an embryonic- like cells and tissues properties.