Developmental retardation of the Japanese quail embryo under the influence of dexamethasone.

Cultured Japanese quail embryos were treated with various doses of dexamethasone on day 2 and in part also on day 5. The treatment lead to a significant delay of development. This was demonstrated by means of developmental (growth rate, developmental stage), histological and metabolic (excreted uric acid, protein synthesis) parameters. The effect was intensified when the agent was administered into the subembryonic liquid instead of the albumen. This is due to the fact that a higher dilution is expected when the agent is deposited into the albumen. In conclusion Japanese quail embryos respond to exogenous glucocorticoids, at a very early stage of development and at a comparatively low concentration with a depression of development.