Biopolymers and cell. 2005; 21 (3): 250 - 257

The role of natural retinoids in the formation of avian cardiovascular system

E. V. Kostetskaia, I. E. Kostetskii, M. H. Zile

The retinoid knockout model system was used to examine the biological activity of various natural retinoids in early cardiovascular development. We have demonstrated that all-trans-, 9-cis-, 4-oxo-, and didehydro-retinoic acids, and all-trans-retinol can maintain alone normal development of cardiovascular system. Vitamin A-deficient embryos developed normally only when retinoids were added during early stages of embryogenesis, not later than at 5-somite stage. Early in development the vitamin A deficiency downregulates the expression of the retinoic acid receptor RARb₂ in the heart and in the developing central nervous system. All tested retinoids induced the expression of RARb₂ in the same embryonic structures of the vitamin A-deficent quail embryos where RARb₂ is normally expressed. But the level of induction differs for different retinoids. Therefore, our studies provide the strong evidence for the complete requirement of avian embryogenesis for retinoids and their receptor.

Key words: cardiovascular system, retinoids, vitamin A-deficiency, retinoic acid receptor, early embryogenesis.