Hydrocortisone receptors and their nuclear acceptor sites in the developing chick retina

Abstract

In the embryonic chick retina, hydrocortisone (HC) elicits an age-dependent induction of glutamine synthetase (GS). Cytoplasmic HC-receptors from retinas of both preinducible (7-day) and inducible (12-day) stages of embryonic development display similar chromatographic and sedimentation properties. Specific, saturable receptor-hydrocortisone (R-HC) acceptor sites are detectable in nuclei from retinas of both stages. The concentration of these sites in the chromatin from 7-day retina is greater than that in the 12-day retina. These results suggest that the development of CS inductibility in the retina is eitehr due to ontogenic changes in the specificity of the receptor-acceptor interaction or due to developmental changes affecting the transcription or translation of GS mRNA.