Periodic histopathological and ultrastructural changes of excess vitamin A on oral carcinogenesis

In this study initially a precancerous condition, leukoplakia, was develop at 6 weeks treatment of DMBA whereas in the animals treated both DMBA + Vit. A, leukoplakia was seen at 10 weeks followed by papilloma or nodules at 12 weeks. Tumours induced by DMBA were more in number than DMBA + Vit. A treated tumours. The histological and ultrastructural changes were enhanced and prominent in DMBA treated animals at 12 weeks, where as these changes were considerably less in animals treated with DMBA + vit. A at 12 weeks.