Fig. 5.
Pitx2flox/−;Tg(Tshb-cre) mice have blunted TSH response to hypothyroidism. Pitx2flox/−;Tg(Tshb-cre) (transgenics) mice and controls were treated for 4 wk with a low-iodine diet enriched in PTU (0.15%). A, Serum levels of total T4 were significantly decreased at the end of the treatment in transgenics (dark gray) and controls (light gray) relative to untreated mice. ***, P < 0.001. B, Tshb, Pitx1, and Cga transcripts quantified by RT-PCR in pituitaries from treated and untreated control and transgenic mice. Results are presented on a log scale depicting the effect of PTU treatment on each genotype group. ***, P < 0.001; **, P < 0.01. C, TSH levels in serum of transgenics (dark gray) and controls (light gray) were measured by RIA and presented on a logarithmic scale. *, P < 0.05.