| Abstrakt: |
A state of pure vitamin A deficiency, without any clinical manifestations, rapidly induces a stimulation of ornithine decarboxylase (ODC) activity and some oesophageal mucosal abnormalities (hyperkeratosis, dyskeratosis, cytonuclear abnormalities) in rats treated with N-nitrosobenzylmethylamine (NBMA). Retinol deficient rats fed with retinoïc acid (all-trans) show a mucosal ODC induction, but no morphological lesion. The association of retinoïc acid + retinol, as does retinol alone, prevents simultaneously histological lesions and enzymatic induction. In the liver of vitamin A deficient rats treated with NBMA, a stimulation of the ODC system, without any macroscopical lesions, has been observed. |
