Vitamin A deficiency and tri-iodothyronine action at the cellular level in the rat.

Young rats were given a diet with or without vitamin A for a period of 7 weeks. In rats on the vitamin A-deficient diet, the formation of tri-iodothyronine (T3) complexes with nuclear proteins was reduced, and Scatchard analysis showed a decreased capacity of nuclear T3 receptors. In these rats, a decrease in growth and a decrease in the activity of lipogenic enzymes (glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase and L-malate dehydrogenase) occurred, which could be related to the decreased formation of T3-nuclear protein complexes.