[Retinoic acid and steroidogenesis]

When Wistar and Sprague-Dawley rats fed from weaning on a vitamin A and provitamin A deficient diet are supplemented with retinoic acid, they mature into adults whose general physical conditions and weight are comparable with those of retinol supplemented animals. However, the adrenal cortex, testes and ovaries delta 5-3 beta hydroxysteroid deshydrogenases-delta 5-delta 4-3-oxosteroide isomerases are in all cases strongly decreased compared with those of retinol supplemented animals. These results are reproducible only if the mothers' reserves in vitamin A are about 50 gamma/g of hepatic tissue and if the animals are weaned between the 19th and 21st day. These results obtained under these strictly defined conditions demonstrate the importance of the "biochemical lesion" which causes steroidogenesis perturbations induced by the vitamin A deficiency. The experimental data are discussed in the light of the recent findings concerning the direct role of the vitamin A in the transglycosylation reactions (Luigi M. de Luca, Vitamins and Hormones, 1977, 35, 1-57).