title: Ontogenesis of nuclear T3 receptors in primary cultured astrocytes and neurons.
abstract: Nuclear T3 receptor (NTR) have been characterized in separated cultures of neurons and astrocytes. Scatchard analysis indicated the presence of a single class of high-affinity sites in both cell lines. The apparent equilibrium association constant ranged from 1.80 +/- 0.41 X 10(10) M-1 to 3.27 +/- 0.74 +/- 10(10) M-1 in neurons and from 1.01 +/- 0.09 to 1.80 +/- 0.73 X 10(10) M-1 in astrocytes depending on the time in culture. In neurons, the maximal binding capacity (MBC) increased from 0.049 +/- 0.008 ng T3/mg DNA to 0.328 +/- 0.052 ng T3/mg DNA between 3 and 12 days of culture. In astrocytes, the changes in MBC were less pronounced ranging from a minimum of 0.095 +/- 0.024 ng T3/mg DNA at the 7th day of culture to a maximum of 0.198 +/- 0.048 ng T3/mg DNA at the 21st day. The relative binding affinity of the receptor for thyroid hormone analogs was in the order TRIAC greater than L-T3 greater than D-T3 greater than L-T4 in both cell lines. These results show that nuclear T3 receptors similar to those found in vivo are present in primary cultures of both astrocytes and neurons.
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000032:analysis*; D001921:Brain / Q000166:cytology; D001923:Brain Chemistry; D002454:Cell Differentiation; D002478:Cells, Cultured; D009474:Neurons / Q000032:analysis; D011869:Radioligand Assay; D051381:Rats; D011919:Rats, Inbred Strains; D011988:Receptors, Thyroid Hormone / Q000032:analysis*
chemical_list: D011988:Receptors, Thyroid Hormone