Figure 4.

Effect of TSH to enhance dissociation of prebound ¹²⁵I-TSH in cells expressing TSHRs alone, TSHRs and L252Ps, or TSHRs and C41Ss. Cells were transfected with TSHR alone (0.0025 μg TSHR plasmid+0.5 μg empty plasmid), 0.5 μg L252P plasmid + 0.025 μg TSHR plasmid, or 0.5 μg C41S plasmid + 0.025 μg TSHR plasmid. After 48 or 72 h, ¹²⁵I-TSH dissociation was performed as described in Materials and Methods in the absence or presence of 100 mU/ml TSH. TSH effect was calculated as the difference between percentages of total ¹²⁵I-TSH dissociated in the presence and absence of 100 mU/ml TSH. Results shown are from 2 experiments performed in triplicate. Bars represent means ± se.