Incubation of chick embryo skin and mouse colon tumour 26 with [3H]retinoic acid resulted in the formation of a complex of retinoic acid and its cellular binding protein both in cytosol and in nuclei. Formation of the ligand—protein complex was temperature-dependent and increased with increases in retinoic acid concentration in the incubation medium. About 3—8% of the ligand present in the cytosol was associated with the nuclei.
Cellular uptake of retinoic acid in vitro