Prolonged influence of a single neonatal steroid (dexamethasone) treatment on thymocytic steroid binding.

Treatment of newborn rats with a single low dose of dexamethasone gave rise to lasting alteration of thymocytic receptor binding capacity. The receptors decreased markedly in number, while their affinity for the hormone was slightly increased. It appears that imprinting with a steroid changes the receptor--hormone relationship in the adult organism.