Article Figures & Data
Figures
- FIGURE 1.
Immunocytochemical staining of TSHR on FRTL-5 cells. A mouse monoclonal TSHR antibody was used as primary antibody. TSH-treated FRTL-5 cells: (A) Negative control. (B) Primary antibody. TSH-starved FRTL-5: (C) Negative control. (D) Primary antibody.
- FIGURE 2.
Uptake of 131I in TSH-treated FRTL-5 thyroid cells. H89 significantly blocked TSH-induced uptake of 131I by 53.8% ± 16.7% (*P < 0.001, n = 8) confirming PKA-mediated increase of radioiodide transport by TSH. Values are mean ± SD of 2 independent experiments, each performed in quadruplicate. NS = not significant (P > 0.05).
- FIGURE 3.
Representative Western blot analysis of GLUT-1 expression in TSH-treated and untreated FRTL-5 rat thyroid cells. Cells were cultured in absence of TSH for 3 d, and TSH (1 mU/mL) was added subsequently. Membrane preparations were obtained as described. Lines A, B, and C show expression of GLUT-1 in membranes of TSH-treated cells (different protein concentrations were loaded on the gel: A, 3.7 μg; B, 7.4 μg; C, 11 μg). Line D shows rat GLUT-1–positive control (PC-Glut-1; FabGennix). Lines E and F visualize GLUT-1 expression of TSH-untreated FRTL-5 cells (E, 3.7 μg; F, 7.4 μg of protein, respectively). The ratio of GLUT-1 signal intensity between TSH-treated (+TSH) and -untreated (−TSH) cells in membrane preparations of equal whole protein mass was determined to be 1.60 ± 0.07 (n = 3).
- FIGURE 4.
Inhibition of (Bu)2cAMP- and TSH-induced increase of 18F-FDG uptake in FRTL-5 cells by the PI3-kinase inhibitor wortmannin. Differences in 18F-FDG uptake values between TSH-activated FRTL-5 cells (+TSH) and TSH-treated cells in the presence of the selective PI3-kinase inhibitor wortmannin (1 μmol/L) were statistically significant (*P < 0.001, n = 20). Values are mean ± SD of 5 independent experiments, each performed in quadruplicate.
- FIGURE 5.
Effect of selective PKA inhibitor H89 on (Bu)2cAMP- and TSH-induced 18F-FDG uptake in FRTL-5 cells. H89 did not produce a significant effect on 18F-FDG uptake at concentrations between 0.25 and 25 μmol/L (P > 0.05, n = 4). Values are mean ± SD of 1 typical experiment performed in quadruplicate. Three independent similar experiments yielded qualitatively identical results. c = concentration.
