Abstract: | The ability of the isolated embryonic chick retina (12 days) to bind a steroid (cortisol) decreases when the tissue is dissociated; the extent of this decrease depends upon the method of dissociation. Trypsin and mechanical dissociation decreased cortisol binding slightly; papain dissociation essentially eliminated it. Cortisol binding decreased with time in culture in both whole retina and monolayer cultures; this decrease may reflect, in part, a similar development decrease in ovo. Inducibility of glutamine synthetase in whole retinas and retinal monolayers prepared with either trypsin or papain also decreased with time in culture. For whole and trypsin-dissociated retinas, the drop in inducibility correlates with the drop in cortisol-binding capacity. This was not the case for monolayer cultures prepared by papain dissociation. |